What do I upgrade first?

Well, of all things in your clan, you should always strive to upgrade your town hall.(TH)
If you are not much of an aggressive attacker (such as myself), the best way to earn elixir (¥) and cash ($) is to upgrade your collectors and mines. To keep these as safe as possible, focus on upgrading walls and defenses. Otherwise, when you are attacked, you will be all like !!! So, that is what I currently have to say. I hope that helps!!!!

There's no real response here. It's 100% up to you. I'd say max out your defense for your current townhall then walls next if you want. If you don't want to attack then upgrade your gold and elixer. GL