When i will be able to buy other weapons?

[Dawido]

Im now have 12 hours in game, yet i still can buy only starter weapons at Vault 13.
When i will be able to buy stuff like handgun shotgun, SMG, or other cybernetic weapons?

[Nope]

Exploring and killing bosses
Edit: completing campaign on Veteran, Nightmare and Apocalypse will unlock a bunch of weapons at Brabus too

[Suzaku]

When killing bosses, they will drop special materials. Some of them are used to craft new weapons at the woman fixing the engine in the main building.

That, and sometimes finding weapons out in the world, usually well hidden.

[Xaelon]

Originally posted by Nope:

Exploring and killing bosses
Edit: completing campaign on Veteran, Nightmare and Apocalypse will unlock a bunch of weapons at Brabus too

^
This. Outside of the weapons you unlock by beating the campaign on Veteran and above Brabus doesn't get more guns to sell.

If you want anything else you'll have to go find it. All of the non-boss weapons in this game are hidden. Most of them are behind locked doors and/or in hidden areas that don't show up on your map.

Beating an area for the first time in your campaign unlocks Adventure Mode for that area which allows you to replay it without effecting your campaign progress. The areas in this game have a pretty substantial amount of different events and dungeons so replaying an area will give you different loot to collect.

If you're not a fan of hunting down secrets yourself you can always consult the wiki: https://remnant2.wiki.fextralife.com/Remnant+2+Wiki

[Cutlass Jack]

Originally posted by Dewido8:

Im now have 12 hours in game, yet i still can buy only starter weapons at Vault 13.
When i will be able to buy stuff like handgun shotgun, SMG, or other cybernetic weapons?

Heh Vault 13.

You can actually get the SMG for free in Ward 13. Hint: Start with chest in Ford's office. Your flashlight might have a clue on how to open

[Erudite Xed]

Kill bosses and pray to RNGesus that the mats create a weapon instead of a mod, otherwise play with google up on a second monitor and pray to RNGesus that the obscure puzzle you got gives a weapon and not more jewelry.