In my experience, go into offline raids to get familiar with loot spots, extractions, scav spawns, etc. If you can, have the map on a second monitor.

Also, make sure to wear a headset both in-game and IRL. If you don't, you will forsurely get outgunned by people that do.

Get familiar with the healing system. When I first started, I only bought and used AI-2's, bandages, and splints. There's many types of healing items and they all have different uses, so make sure to research it.

Get over gear fear as quick as you can. This game is a game where you will die A LOT. Also, roubles are very easy to obtain, so if you lose your "beloved" 20 thousand rouble AK in raid, it's not the end of the world.

Your scav runs are super important, use them.

Quests are important, do them.

This game is hard.

This game is unfair.

But,

Can be very rewarding and extremely fun.

Hopefully these tips help, good luck my friend.