Altitude and airspeed are your weapons, once you learn to keep up your airspeed/altitude and when to dump speed for altitude and vice versa you start doing vastly much better.
You win by carefully picking fights where you can hit the enemy without dumping all your speed and altutide, if you are turning circles at low altitude you should consider your plane already forfeit even if you win the turning battle vs your current enemy.
This is called
energy fighting.
altitude = potential energy
airspeed= kinetic energy
You can trade one for the other at will (but it's not a lossless conversion), if you run out of both you are dead as you are a sitting duck. As long as you have more energy than the planes you are fighting against you have a
large advantage over them.
Your engine (especially on lower tier planes) can build energy very slowly (as long as you're not at or near your maximum airspeed, then you will lose airspeed faster than your engine can build it).
It is up to you to use your energy as a resource to fight without running low unless it's absolutely neccesary.
This guy (even though he mumbles and has an accent) has amazing guides on the topic of energy fighting, boom and zoom tactics and has videos for each plane and type of plane (fighter, bombers, heavy bombers etc) for each nation.
https://www.youtube.com/watch?v=qCamYCPolDw
Once you understand the basic principles of energy fighting a whole new learning curve and world of possibilities and experimenting opens up to you.
After that it becomes a matter of knowing the strenghts and weaknesses and understanding the playstyle of each plane (are they better at climbing than you, do they want to boom and zoom, can you outrun them, can you outrun them if you climb? can you outturn them?) .
Alongside that you will do better by learning the weaknesses of each plane (e.g does the plane have thick armor in the rear making it a better idea to shoot its engines) as well as the deadzones for their gunners (especially in the case of bombers)
The weaknesses/playstyles/armor thickness concepts are no different from what you'd learn in a game like world of tanks so they should not intimidate you. You learn this shit while flying the planes yourself as time goes on.
The concept of energy fighting is the biggest thing that will be very alien to people not used to playing combat flight sims/games but it is not hard to grasp and will turn your flying games from endless senseless turning battles to highly entertaining and highly varied gameplay.
Find a playstyle you enjoy and go from there.
e.g pure energy fighter or maybe boom and zoom (dive bombing and diving on enemy fighters steeply then NOT slowing down and turning but climbing back to altitude asap to have another go) or being a sneaky bomber going after the objectives or a flying fortress fighting it out with enemy heavy fighters
This game has a ton of depth, atmosphere in spades due to the awesome graphics and tons of variety.
The last thing I want to say is that the game requires patience to play properly, you can't just fly headfirst into the swarm and start turning , die respawn and start over.
It's as much about energy , positioning , picking the right targets at the right time and escorting bombers/playing objectives as it is about 420 MLG noscope shootbanging at other planes.
I can't talk about the tank mode as I've only spent a few hours with it and it didn't click with me (I played world of tanks for years though)