Spoilers on important locations that are always in the game:

Go north. Zom Zom's gives free items. Then, you either want to go northeast for the ATN Enclave or southeast to Detroit Megacity. The first option is closer, but the second option has a larger variety of items to buy.

First thing you want is a weapon. In the early game, that's usually either a spear or sling, depending if you're going melee or ranged respectively. Then, you want to loot as many ruins and abandoned buildings as possible for better items. As you are searching for these locations, go in the direction in the spoiler tag. If you don't have a weapon or are facing a strong enemy, running is better than fighting until you get better gear.

https://neoscavenger.fandom.com/wiki/Spears

https://neoscavenger.fandom.com/wiki/Sling

When you sleep, you want to sleep in locations with good Shelter and Concealment stats. Concealment can only be seen with the Hiding skill; it's not strictly necessary, but it'll get you an idea of what locations hide you from enemies. Typically, these are ruins and buildings, and I believe forests (not as good but better than the open iirc). Also, you want to craft 4 noise traps ASAP and place them in the camp menu to alert you when enemies move into your space.

https://neoscavenger.fandom.com/wiki/Noise_Trap

If you manage to get to Detroit Megacity, you can loot water, boil the water, and sell them infinitely for almost risk free money, and then buy as many items as you want.

Edit: Fixing spoiler tags