I wanna know which one would be the best for a coastal campaign, its gonna be more beachy and sometimes there's gonna be fights on ships directly like pirates and Kraken, I'm just wondering which one would be the best for this setting. The campaign also has two other people in it.

I think wizards are flexible enough to take advantage of really any setting if you choose spells properly any should work. Instead, you might find out what the other players are doing, and make sure you work well with them. But again, wizards are all about flexibility and really any choice can work well. 

Im not sure we have any supportive roles in our group so could you suggest something thats balanced between dealing damage and dishing out minimal support?

If I were going to play a Wizard it would be an Evocation. What are the other two people playing? If the campaign is set on the sea/coast a lot could be said for playing a Storm Sorcerer, Tempest Cleric, or Druid Circle of the land(Coast)

I know one of thems a druid and thats all, not sure about the other, I'm also pretty set on wizard ngl since its the only class i haven't dipped into, if you have any other tradition suggestions please tell. Also whats Evocation like?

Evocation is the 'blaster' wizard. I would think of it as a ships 'artillery' but, like Xalthu said in a previous post that is what is great about any Wizard is it's versatility. You don't have to pick just blasting spells but, what i like with an evoker is being able to cast a fireball and exclude your friends from the damage. 

Is Abjuration any good?

Wizards are flexible enough that their subclasses don't need to have a huge bearing on how they play. Thematically, Evocation/War Wizard and Divination are the two that make the most sense to try to build a 'ship's wizard' as it were - the first two with the expectation that in combat it's their job to try to be a living cannon and sink the enemy ship, the latter playing more on the sailor's superstitions as well as the utility of them being able to find things when needed (locate object makes the classic search for buried treasure very easy).

However, just in terms of "a wizard who operates well on the coast" the answer is still basically any of them. Keep in mind even the school-centric subclasses can take - and are heavily incentivized to take - spells outside of their school. So definitely don't think of schools as defining what your Wizard does. It will certainly influence what they do, but an Abjuration Wizard isn't super incentivized to have a million abjuration spells, just a couple that they cast a lot (and hey - almost every Wizard brings Shield, Mage Armor, and Counterspell to every party).

Regarding the Abjuration Wizard in particular, Abjuration shines in low-levels (the 2-5ish range) and then again at very high levels (14+) as a very tanky Wizard. In between they're fairly close to your 'baseline' Wizard, though their level 10 ability is very good if you expect to fight other spellcasters. That said, I want to stress that "close to baseline Wizard" is not meant as a bad thing, because even Divination Wizards, who commonly get a rap as the best ones, operate very, very close to baseline Wizards.

If by support you mean healing, wizards don’t do a lot of that. But the Druid should be able to cover most healing. 
Abjuration can be good, sure. And the steady stream of what amount to temporary hp is nice. Nicer still when you can help an ally with it. I guess it does come as close as a wizard gets to a support role, that I can think of. 
Unfortunately the kinds of spells you might want in a more nautical campaign, gust of wind, all the spells involving water (control water is crazy powerful on a boat), are from different schools. You can still cast them, but you won’t get that abjuration benefit from them. 
If you really want to meta-game it, look through and see what spells you think will be useful, and let that guide your choice of school. 

Templar is exactly right about evocation blasting stuff. That’s where all the flashy AoE damage spells are: fireball, chain lightning, meteor swarm, etc. 

Quote from MERAAAAAA >>

Is Abjuration any good?

 Yes, abjuration is really good.

For coastal campaigns, the tradition of wizards isn't that important, the race is more important.

If you're allowed, I'd do Vedalken, but Tritons and Half-Sea Elves could work as well. 

I mean, you can't go wrong with a swashbuckling Bladesinger swinging from the rigging and ripping down the sails on a cutlass!

Quote from Ophidimancer >>

I mean, you can't go wrong with a swashbuckling Bladesinger swinging from the rigging and ripping down the sails on a cutlass!

 That.  Sounds.  AWESOME

A wizard on a beach is no different than one on land. However, the thread did get me realling thinking about campaigns that are highly seafaring in nature - spending most time on ships, fighting pirates and exploring new islands and such. It didn't seem completely on topic with your scenario of being mostly on beaches and only occasionally going a ship, so I made a new thread, but I wanted to mention here in case any of it was useful to you.

Link to thread.