I am a casual pvper myself and found you tube videos that helped. I personally liked Wizbasky. https://www.youtube.com/channel/UCJOJnY4FekQXakw5h79hJ0A/playlists
He narrates and has pop-up tips the whole video that tell you what he was thinking and why. Much better than some that just show the player fighting in the warzone (I am not good enough to know which abilities were being used at any given time).
Watch the opening description as you enter the pvp match. Most have objectives beyond just killing the other team: capturing a node or scoring with the hutt ball. Ask questions if you're not sure what you should be doing - probably best before the match starts or after it ends. You may get a few "unhelpful" comments from time to time, but most people I've met have been friendly or easy to put on my Ignore list.
Stick with your team mates and communicate. Running off on your own is not something you should try unless you're a masochist or really know what your class is capable of. Let your teammates know what you see. If you're on your own and get killed by 3+ of the enemy team, call for help. You may still die but the rest of your team should be able to use that info and attack somewhere else (because it's less defended).
Finally, don't be afraid to run away. Run around a corner to break line of sight, run towards your teammates so they can help. If the enemy doesn't follow, take some time to heal back up and then get back in the mix. You may also find a new spot on the map with a heal or damage buff that just might save the day next time.
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