Multiplayer tips please?

I was alright at Halo 3 and Halo: Reach but with this Halo I get destroyed almost every match I play. If anyone know/has any tips or some strategies or even weapon preferences could you please help me out? I don’t want to sound like some kid wining but I could use any help i can get.

The ghost is very effective in this game, loads of splatters, not sure if armourlock is in this game but noone used it, maybe it has to be bought later on. AR is quite powerful too

a general rule I like to use that works for survivability is - never engage anybody unless you’ve got full shields. if you can’t be at the top of your game, you can give it a few seconds to fill up most of the time.