look up shift's unturned modeling tutorial
i gave this a try, but it doesn't seem like that good of a tutorial, to be honest?
he's using a lot more polygons than needed (making straight surfaces by moving a lot of vertices by hand and creating a lot of unnecessary cubes?) and he just straight up goes from one model to another between tutorials 2 and 3 which kinda forgets everything up (plus the tut 3 model has a bit of bevel which he never explained)
this is how far i got before i gave up:

I recommend looking up Blender Cookie tutorials on Youtube. They show all the basics.
these are the best tutorials i've found so far, and they are featured on blender's official tutorial page; however, as i said, most of the content is locked behind a paywall - on the other hand, the ones they have on youtube seem to go more in-depth? i'll check it out.
edit: i looked at the modelling tutorial there. its pretty basic but i did learn some stuff. hopefully i can learn some more.