(since I can literally do no damage would I be able to move to Steve and try and take his steel bar?)

(I would be okay giving it to Thursday, I just don't have an action/bonus action free. If I could use the same rule about equiping gear and instead hand it over thats fine with me)

(Unarmed strikes can be done, which deal 1 + Strength modifier damage. If we're playing pass the weapon, it'd have to be on that person's turn to use or manipulate an object to hand it over. Since you were not next to them on their turn, they can't do this turn. Also Steve will be provoking opportunity attacks since he is retreating again and as mentioned the other sand imps are within a couple of feet of the first one.)

Grundam and Steve rush up to the first sand imp, smashing it over the head with the bone and fists. Between them they pummel it as its shape falls away into a small pile on the ground (Sand Imp #1 defeated: 10 damage).

Steve attempts to retreat back, but the other sand imps attempt to claw at him as he flees.

Sand Imp #2's Claw vs. Steve: 12 vs. AC. Hit: 4 piercing damage.
Sand Imp #3's Claw vs. Steve: 23 vs. AC. Hit: 7 piercing damage.
Sand Imp #4's Claw vs. Steve: 7 vs. AC. Hit: 4 piercing damage.

Two of the imps dig their sandy claws into Steve as he attempts to back off, leaving him critically injured. (Steve: 1/10 HP)

Sand Imp's Turns:

Sand Imp #2 lets out a blast of sand at Grundam, into his face. Grundam must succeed on a DC 11 Dexterity Saving Throw or be blinded until the end of the sand imp's next turn.

Sand Imp #3 scratches at Grundam
Claw vs. Grundam: 10 vs. AC. Hit: 5 piercing damage.

Sand Imp #4 also attack Grundam
Claw vs. Grundam: 7 vs. AC. Hit: 5 piercing damage.

The two imps attempt to strike at Grundam, but he narrowly avoids their strikes.

INITIATIVE:

Thursday (10/10 HP)

END OF ROUND

Grumdan (14/15 HP)
Steve (1/10 HP)

Sand Imp 2 (Undamaged)
Sand Imp 3 (Undamaged)
Sand Imp 4 (Undamaged)

His concern is his unarmed strikes plus strength modifier do 0

(it'll be a minimum of 1 point of damage. There are other actions that could be used, for example the dodge or help)

((to be clear I don't want to pass the weapon back and forth, I just want to move to Steve and take it off his belt loop or whatever and then get ready to attack because I'm assuming that would be my standard action for the turn))

 Edit:: if this isn't possible I'll just step back toward Steve and take a dodge action assuming I'm still 10 feet from these things and wont take an AoO

(Ah, you meant the other club. Yeah, as long as he doesn't try to stop you it'll be your Use or Manipulate Object for the turn to pull it from his waistband.)

Okay I'll move back 5 feet and use my bonus action to grab Steve's metal bar from his waistband.

Then I'll move up 15 feet next to Grumdan and attack one of the imps.

((I'm going to work under the assumption that this club and an unarmed strike wont grant sneak attack))

Club attack 15 possible 3 damage

EDIT: I think I got my rolls right. I'm not sure what I add to my attack mod for this club I'm assuming 2? if my str is -1 do I take that away from the d4? or is it just a straight d4?

Dex save 20

Grumdan, seeing the sand coming towards his face, manages to cover his eyes in time, saving them from a gritty feel.

Thursday heads forward, taking the extra club and striking at the next sand imp. Her strike is true, but she would feel much more at home with a dagger. (Sand Imp #2: 2 damage.)

(OOC: To answer your question, unfortunately you would add your -1 penalty to attack and damage rolls. Fortunately you still hit, but your damage is 1 less. Just keep in mind a minimum damage roll will still be 1, even if you roll an overall 0.)

INITIATIVE:

Grumdan (14/15 HP)
Steve (1/10 HP)

Sand Imp 2 (2 damage)
Sand Imp 3 (Undamaged)
Sand Imp 4 (Undamaged)

Thursday (10/10 HP)

END OF ROUND

Grundam takes a swing at imp 3. 

Attack: 20 Damage: 4

Grumdan swings at the sand imp, but it manages to duck beneath the wide swing, avoiding the attack.

INITIATIVE:

Steve (1/10 HP)

Sand Imp 2 (2 damage)
Sand Imp 3 (Undamaged)
Sand Imp 4 (Undamaged)

Thursday (10/10 HP)

END OF ROUND

Grumdan (14/15 HP)

Steve keeps his distance, maintaining 30 feet between him and the nearest imp.

Imp's Turns

The imps attempt to flail at Grumdan again, one of them flinging sand at his face while the other two both go for a leg each.

Sand Imp #2's Claw vs. Grumdan: 18 vs. AC. Hit: 3 piercing damage.
Sand Imp #3's Claw vs. Grumdan: 19 vs. AC. Hit: 4 piercing damage.
Sand Imp #4's Claw vs. Grumdan: DC 11 Dexterity Saving Throw, or be blinded until the end of the sand imp's next turn.

(Grumdan is raging, right?) Grumdan takes some superficial wounds, warded from by his mighty burl as he fights angrily (Grumdan: 11/15 HP)

INITIATIVE:

Thursday (10/10 HP)

END OF ROUND

Grumdan (11/15 HP)
Steve (1/10 HP)

Sand Imp 2 (2 damage)
Sand Imp 3 (Undamaged)
Sand Imp 4 (Undamaged)

Thursday hones in on the damaged imp and swings. 

Club attack 14 possible 3 damage

Grundam dex save 15

Yeah I should probably be raging. Never played a barbarian before 

(It's all good. It's the experimental fight, so we're all in a learning experience)

Grumdan manages to avoid the blast of sand again, while Thursday backs him up with a well placed swing, batting one of the sand imps aside, but not destroying it. (Sand Imp #2: 5 damage)

INITIATIVE:

Grumdan (11/15 HP, raging 1 round)
Steve (1/10 HP,)

Sand Imp 2 (5 damage)
Sand Imp 3 (Undamaged)
Sand Imp 4 (Undamaged)

Thursday (10/10 HP)

END OF ROUND

The imps seem a little distracted by the mighty barbarian, attempting to burrow their sandy hands into his flesh.

Grundam continues his rage against imp 2. “You go no where,” I say as I try to grab the imp. 

Athletics: 11

Athletics: 13

(You get advantage on Strength-based skill checks, so feel free to roll a second die if you want)

Grumdan reaches over for the imp as it attempts to slip away from his grasping hand.

Sand Imp's Acrobatics check: 5

Unfortunately the imp is too nimble to grab, the sand flowing between his big brutish fingers.