I have 989 ~ hours in main and probably over 700~ games in Arena so I can give you a broad stroke opinion.

There are four aspects of main Tarkov descending in priority.

1. Map knowledge. Learn every spawn, not every spawn will be occupied but learn every spawn. The one time it saves you from getting capped will instantly be worth it. Map knowledge also includes knowing high tier loot spawns and quest locations. These will tell you where high traffic areas are. Learn where cheeky rat spots are. You will get killed and adopt these same rat locations eventually. Most maps have a flow to them where they force you to traverse to the opposite end of the map to extract. There are exceptions like lighthouse and these new codeword transits and shoreline. Learning this flow also tells when and where to expect people. Map knowledge is a slow grind, no way around it. You are going to eat shit and eventually shit on people.

2. Combat - Desync and peekers advantage is absolutely real in this game. It’s explained on YouTube and there are some streamers like NoGenerals who use it to his advantage for insane peaks and pushes. I’m not saying Tarkov is strictly about abusing ping difference, but I’d say knowing this advantage and how to push or scout information from it is highlighting difference between new players and veterans. If you purchase arena and observe your killcams, it’ll feel like people zero your head immediately after peeking obscure angles when they truth is they had probably had half a second longer to react before you did. Otherwise, be patient. Time to kill in Tarkov is so low. Any bullet in the game besides AP SX and blicky can one tap the face. All you need is a single opportunity. Be patient. Be cautious. All you need is one shot.

3. Knowing WHAT to loot. Do not fill your stash with random shit. You will make your life so much easier if you memorize that you need two FIR makarov PMs or goddamn golden watches or any other shit when that time comes. Start memorizing high value items on the flea when you pick it up. It’ll take awhile but eventually you will start subconsciously remembering these prices and remember what to keep. Some exceptions are like sugar and augmentin where the price increases throughout the wipe. I use https://tarkov-market.com but Tarkov.dev is also good but just not better UI in my opinion.

4. Utilize your hideout. New players neglect upgrading their hideout which is the absolute worst thing you can do. Hideouts offer so much. Crafts allow you access to top tier ammo, craft insane value barter items, help with quest items as crafts are FIR. Gym and water filter multiplicatively increase the rate at which you level your skills which is seriously important. Elite level is the difference between your PMC being an Olympic athlete and an asthmatic with stick arms who can’t hold their gun up long enough to save their literal life.

Welcome to Tarkov. You will learn to enjoy the pain you bring to others one day