Hey. For a lot of people, playing halo for the first time can be a not so pleasant experience. I'm going to hopefully give you some advice to help you learn quickly and get better.

For starting out the best thing you can do is learn everything you can about how the game works. This includes how to become proficient with all the weapons, where all the weapons/powerups are located on the maps, and learning the maps itself.

Next learn your playing style. Whether you like being a frontline fighter, using weapons such as sword, shotgun, mauler, and assault riffle, or if you prefer staying back and picking people off with battle rifles, covenant carbines, spartan lazers, and sniper rifles, is up to you.

Controller type is also something a beginner needs to check out. Different button layouts can help you jump, or throw grenades better, as well as punch faster. You have to find what you're comfortable with. The sensitivity of your controller plays a big role as well, too fast and you tend to miss your target a lot, too slow and you tend to not be able to turn and end up dying a lot.

That's pretty much it for starting out. Play some custom games with other noobs, or check out forge to get used to the maps and playing styles that fit you.

 Alright so you've mastered the basics, and are beating noobs left and right, but you run into those occasional matches where it's just embarrasing.  This section is going to show you what people who are really good use.

Radar/crouching.  Seriously this thing can make or break matches.  Radar is probably one of the most important things you have, especially if you use weapons such as sword/shotgun/mauler, or if u like to sit around corners and lead people with grenades.  Crouching is also important because it keeps you off of other people's radar, making such weapons as mentioned above, useless.

Weapons have a timer for respawn.  Weapons respawn time is set, so if it has a 4 minute respawn time, then every 4 minutes it respawns.  If you are on a stage with rockets, or lazer, or anything powerful that can turn the tide of battle, remember how long ago the weapon was taken, and keep track in your mind how long till it respawns.

Team Chat.  HAVE A MIC!  if you don't have a mic, you should burn in hell for being gay.  seriously mics are important.  Not for screaming in your teammates ear, because thats annoying and people wont want to play with you, but so that you can give out important infromation.  If you are fighting a group of people, that all would die in one shot, call it out, and if a teammate is nearby, they can clear the room with a grenade, or rocket, or just run in and shoot them all once, and bam, easy kills.  Also if you had a powerful weapon, or an enemy is camping a corner with a sword, let your teammates know so they can deal with it.  It can be extremely useful, if playing with others that play as a team.