Getting into Tarkov as a new player this late in the game is incredibly difficult. Map knowledge alone can take an extremely long time to complete. On top of that, there are quests that span multiple maps. If you die on the 2nd map you have to restart back on the first map. If you start late in a wipe players may be much more aggressive due to having so much in their bank and access to such high-end load-outs that you may struggle. Getting to level 15 can be difficult if you are a new player. At Level 15 that is when you can access the flea market and start getting access to good loadouts.
Tarkov is an extremely fun game that I believe pushes a lot of new players away. I struggled online trying to learn maps and complete quests. This can be especially hard if you don't have friends who understand the game, to begin with. Now don't get me wrong I love playing Tarkov online but it can be really frustrating as I don't have the full knowledge that other plays have from playing so long. I found the offline mode to be frustrating because it was still hard to test guns and learn how to use them. Modding was also difficult because I couldn't access the flea, and my traders were at such a low level. That's when I discovered Escape from Tarkov Single player.
This mod requires you to own Tarkov from the official developers. They do not support people pirating the game. You can find the tutorial that I used to get this set up right here. Please note while I have not seen evidence of the developers banning players for using this it is technically against terms. They could ban you so please do this at your own risk.
The mod essentially lets you run the server on your own PC and does take increased resources to run it. The more bots on the server the lower your frames will go. It works just like online Tarkov, but the PMC and fleamarket are run by bots. The mods below allow you to alter the PMC AI and make them easier or harder depending on how good you are. You can progress through the game just like you would normally, and lets you change a lot of things. For instance, the Flea Market is available at level 5 for me. This means all the quests and maps work just like online. Honestly, if you really wanted to this mod could be harder than Online. The flea market is run by bots as well. You can buy and sell stuff on there just like the live game.
SP Tarkov even has mods available for you to use. I recommend ServerValueModifier, ZEreshkigal-AllinOneMod, and zFin-AITweaks. You can find mods on the official website under hub right here. ServerValueModifier lets you tweak all kinds of settings about the server from a GUI. All in One Mod is great as it has even more settings and the ability to change the flea market level requirements. zFin AI Tweaks lets you make PMCs/Scavs harder or easier. The default setting is 40 AI on the map max. This can really slow down your CPU. So you may need to turn this down. It has a lot of setting for their behavior, such as not allowing them to aim for your head. This setting helps with the random head eyes from across the map.
Realistically I really enjoy this mod. It's definitely helped me get back into Tarkov, and I think it's a great tool for new players as well. It allows you to progress and practice the maps and quests. You can tone the game down if you're struggling or crank up the difficulty if you're a god.