You'll want to go with circle of the moon as your subclass at level 2. Until then, you could use hide armor if you wanted. That'd give you one more AC. You could consider getting up to 14 dexterity to help when you're out of wild shape. This will also help you at level one. The extra initiative is always nice too!
As for spells, bark skin will be very helpful if you're going to be tanking. You can't cast spells while wild shaped, but you can still concentrate on one (and control it if the spell allows it). Bark skin will keep your AC at least 16. Most beasts have fairly low AC. A brown bear, which will be your best taking option at level two and for a while after, only has 11. That's a pretty big bonus! You'll get this at level 3.
At level one your best spell might be healing word. It's a bonus action heal and you can still take a whack with your weapon.
You may want to switch to a club or quarterstaff and use shillelagh. It's a fantastic cantrip at low levels.
When you take damage while concentrating on a spell, you'll have to pass a concentration check (which is basically a Constitution check). That means a high Constitution will be important! Consider getting resilient Constitution feat for proficiency in Constitution saves or the war caster feat which gives you advantage on concentration checks at level 4.
Hope this helps with those first few levels! Let me know if you have any specific questions!
Everything Kendis said is really good advice. I'd definitely advise swapping your dex and charisma because CHA isn't too important for a druid, and you can get the bump up to 15 AC and +2 Initiative. Shillelagh is also kind of an essential especially if you're going to be in the front lines, it'll be the bread and butter of how you fight at early levels when you don't have wildshape available. A shillelagh'd club is strictly better than your scimitar
Keep in mind that Druid spellcasting is heavily geared towards battlefield control. You might want to consider taking spells that help you fulfill the tank role over straight damage spells. Entangle is great at early levels, you can snare enemies and make sure they can only attack you, and then go to town on them in a wildshape form. If you can get the Warcaster Feat, you'll have advantage on concentration checks which is important if you want to be able to use any of your concentration spells while tanking. Front-line type moon druids typically make better use of warcaster than other druids.