How do you get your MU and character tech knowledge if you don't play online? Thats legitimately the best place to get tech knowledge and character experience besides major tournaments
Footage of others playing shows you all the tech, labbing it shows you how to beat it.
That is a big part of it.
Also I have been traveling a lot more for this game in the last 6 months than any other game to date. I attend every local (We have a pretty good number of characters repped, though admittedly not all at the highest level), attend events in neighboring states and have attended several majors for the game as well as a trip to GGA.
Eevee and I also play a lot and both he and Kenshinoyo have picked up a fair number of characters which while we don't have intimate MU knowledge about them, we learn all the tech we can find to practice playing against it and if need be have potential CPs.
As you may have noticed, I am also extremely active on these forums, and try to read then test pretty much everything I come across so that I may know if it's useful and/or worth using. I then pass it on to whoever in my scene will benefit from it the most (No seriously, I do give my scene homework; sometimes to everyone at once, sometimes I will tell people individually to "go home and work on this". I am even working on a local power ranking right now for my scene to rank every aspect of their game, their strengths, their weaknesses, and what they need to do to improve. I put in a LOT of work to expand and improve my scene, as anyone in it can attest.).
Finally, I watch every stream I have time to watch. I can't watch every local, but I try to watch at least one a week just to see how each scene is evolving as well as training myself to try and catch people's faults faster, which has been helping me more and more in game.
There are a lot of different ways to level up and a lot of different ways to practice. There are both good and bad ways. For example online won't help you if you play randoms exclusively. Training mode won't help you much if you're exclusively practicing combos. Offline practice won't help you if you don't level up your training partners. How you practice is just as important as how much you practice.
Sorry for the long rant, especially since you probably already knew most of this stuff, but this is actually something that's been a topic that I have been bringing up a lot recently, especially to a few of the guys in my scene who do practice a lot but haven't really been improving much lately.