Want to survive the mean streets of Los Santos?
GTA Online is rough country. You're likely going to encounter nasty folk during your virtual adventures in Blaine County and Los Santos who would much rather riddle you with holes than stop for friendly conversation. Quite literally saying "hi" is likely to send bullets flying your way.
In this kind of an environment knowing your way around the game's guns, other weapons and shooting mechanics can mean the difference between life and waiting for a respawn. Or, you know, death. Winning a firefight in GTA Online comes down to more than just having the bigger gun and pulling the trigger whenever the reticle turns red though.
Whether you're new to gaming as a whole or are just new to GTA 5, these tips will go a long way to helping you not decorate the pavement with your innards each time someone decides to pre-emptive strike your virtual ass. Not every gun is made equal and techniques matter.
Weapon Selection Interface/GUI
First of all, let's tackle the initial and possibly most bothersome opponent you'll encounter: the weapon selection interface. GTA Online's weapon wheel can very quickly become an unmanageable mess if you're the kind of person who likes to stock up on weapons. Your character will always carry every weapon you own around, and you can't change the order in which they're located on the weapon wheel.

Unless you want to get bogged down in the middle of a battle scrolling through a dozen guns to get the one you actually want, we suggest dropping all the guns you don't like or won't need. Granted, you'll need to manually do this each time the game re-initializes, which will quickly become a pain. Once you have the money for it, we definitely suggest buying an executive office with the gun locker add-on, as this will allow you to customize your loadout. Granted, this works for free roam only.
Realistically, you'll never actually make much use of any of the SMGs, so you might as well leave that tab alone. When it comes to rifles, only keep the Compact Rifle for use on a bike, and the Special Carbine (some swear by the Advanced Rifle, so take your pick between the two). In the shotgun tab, drop everything beyond the Assault shotty, in pistols only keep the AP and Heavy Revolver (Marksman too for advanced players) and the only throwables you'll need are the sticky bomb and the proximity mine.
When it comes to melee weapons, keep in mind that all have identical damage, but the knife has a higher rate of attack, making it the best of the lot, so you can drop the others. Once you've unencumbered yourself, you're ready for some action.