Yeah, starter pistol's shit. Just aim at the center of their mass and shoot till they drop. That's probably the hardest part, getting used to the horrible inaccuracy of most of the weapons. Soon enough you'll get an AKm 74/2u, which is more accurate, and then it's not long till you get a full AK 74, which handles like a dream compared to the earlier guns. Then you hit the nato guns, which actually shoot where you point them!
Also, the easiest approach is to circle around the compound and attack through the alley on the north side, next to the big house where the hostage is, take the higher ground, and ambush the bandits that pour in. Watch out, there's a ladder on the courtyard side, but I don't know if the AI can use ladders. I don't remember it ever doing so...
STALKER tends to require a lot of strategic thinking, especially early on. Later it becomes natural, and matters a little less because you get weapons that actually hit what you're aiming for.
Arsenal advice for mid-to-late game: nato guns. The TRs 301 is right up next to the best guns in the game, it's accurate, has heavy damage, and can fit a scope, silencer, and grenade launcher. The... GP(GS? I can't recall the second letter off the top of my head) 37 is more accurate, and has higher damage, but its scope is built in, so it's not suitable for close-quarters combat. A TRs 301, a dragunov sniper rifle (available from a duty merchant, along with its ammo), and a UDP compact form a good loadout, albeit a heavy one.