Weird lag spikes/stutters on singleplayer

Hello, I have recently installed Garry’s Mod again on my PC, and i seem to keep having this problem, i think it has nothing to do with my PC specs (altough it’s almost a toaster)
I managed to play other source games like Portal with no FPS troubles at all, but the problem is this:

When i spawn in the world (world finishes loading…) and i move for the first time, i get a little bit of a lag spike, or a stutter, lasts about 0.50 secs, then i can go back to play normally.
This also happens when killing a NPC, pressing the numbers (1, 2, 3, 4, 5, etc.) to choose weapons, and also when i shoot a weapon, those are the only stutters i get, excluding those, i can play pretty well with 130 - 200fps on Flatgrass on high settings (except for AA)… Anyways, here are my PC specs:

-Intel Celeron G530 2.4GHz
-Intel HD Graphics Family
-x32 Operating system (Win10)

Yeah, sorry for the shitty PC, as i’m from Venezuela, things are really difficult to get here…

By the way! these lags only happen the first few times i do this on a recently loaded map, then it goes back to normal…

Source games do not support Intel integrated graphics, and that low of RAM.

Oh, well… i guess i give up on this… back to playing minesweeper at 5fps lmao