What to upgrade first? TH7

[kather]

Barracks and new army camps. That will help you a lot in your raid.

[Dpino]

Ditto what everybody has been saying about the army camps and barracks. I'd also be sure to make Teslas a priority very early; you don't want to fall behind on your tesla upgrades because they take a while. And even though they seem expensive at first they actually aren't that bad to upgrade cost-wise because they don't double in cost with each upgrade like most of the other defenses.

[TullSadum]

I would increase offensive strength first. Add the new Army Camp and new Barracks first and upgrade Army Camps as soon as possible. You can loot much more often with the extra Barracks and more effectively with the 50 additional troops. Then upgrade spell factory so you have 3 spells. Upgrade Barracks to level 9 if you want to do Drag Attacks in war.

For defense get all the new defenses and then upgrade to TH 6 level. Add Teslas and then upgrade Tesla, Wizard Tower, Mortar, Air Defense, Archer Tower and Cannons in that order.

I found one builder on Tesla/AirDefense and one on all other defenses worked well.

Solid advice here
except with the order of defencive building upgrades, at TH7 you're facing giant healer attacks mostly and therefore should do cannons and archertowers early, then the tesals and WT, you can leave Mortar and AD until late.
Also get your dex storage once your trophies are high enough for you to find dex. Don't worry on pushing for BK, just let the dex slowly accumulate and go for it full throttle once you hit 7k. Stay away from training dark troops until then, to keep you from spending hard earned dex.

Have Fun
TS