I'm not sure if it can fit your criteria but there's this manga called "Katekyo Hitman Reborn" where a spineless guy gets picked up by a very strong baby-looking tutor to be the head of a mafia group. He's very weak but he gets trained and gets obviously stronger, gets comrades, gets weapons and all. It's quite good.
Legend of the Northern Blade (his teacher was his father who rather than actually 'teaching' him...he kinda left clues. You'll know if u read it)
Gosu
Boku no hero academia (lol)
Gintama
I know more but i cant remember...theres one good one at the top of my mind but i cant seem to remember it ┗( T﹏T )┛
I'm in the mood of this type of mangas, webtoons, manhuas and I like to read everything similar to this:
Eleceed
The breaker
Kenichi
Veritas...
I want it to be based on student-teacher where the teacher is one of the strongest known who decides to train a normal person who becomes strong over time.
If you understand(๑•ㅂ•)و✧