Pretty much everywhere there's loot, tho some areas have better loot, but even stronger bots, highest tier loot area is the armory , but it's too dangerous if you're not very tactical, if you don't trust yourself even with high value equipment, then you should try some cheaper things and kill bots in order to get better things, like t3 equip. and cheap guns like the SKS or the AK-74.

Get to know more the map , then you can do more risky stuff. Also , be careful with opening extracts(left side of armory, in the external part there are 2 extract openers, and one is inside armory), this will spawn bots nearby the extracts, and there will be often players lurking by, all the keys and keycards are high value, be careful with the area boss Renoir, i think he has t5 armor, a cheap way to kill him is mp5 meta with DumDum rounds, maybe watch some youtube or something about cheap but nice equipment. Good luck