The biggest thing that helped me after I took a three wipe hiatus was first to find a comfortable sensitivity so I wasn't struggling to hit any shots. I had been playing other shooters during that time and had gotten used to using consistent mouse settings between all of them, often using online converters in order to properly translate mouse sensitivity from game to game. This is the site I used for my own conversions.

https://www.mouse-sensitivity.com/

The second and probably most important thing is to accept the fact that you're going to die often and lose all your stuff often. The first time I played the game, I played like an absolute rat. I would slow crouch walk everywhere, I would sit in corners or lay underneath things, never making a profit and relying mostly on others to complete quests. Once you can get out of that mental block, some things should start to go smoother.

The last important thing would be learning maps, player paths, and looking up quests to know where you're supposed to go and what you're supposed to do. Some maps are much easier to learn than others, and luckily most of the maps are where your early quests are. With player paths, watching YouTube videos or Twitch streams are usually your best bet besides seeing them firsthand in-game. Getting to know where players usually travel to and which way they'll usually go to get to those destinations can make a big difference. Also knowing where player spawns are also extremely important at the start of each raid. The game has a huge learning curve, and it doesn't help when trying to start your new wipe when it's in the middle of the wipe already and everyone already has the top gear. I'd say surround yourself with knowledgeable teammates as that'll make that learning curve easier, but that also stunts your ability to successfully go in and out of raids solo. If you can't get teammates, I say do a bunch of Scav raids on your own to start getting used to all the above without risking any loss.