beyond late response, but still gonna give this a try anyways.
https://www.youtube.com/playlist?list=PL4SzCzeORbSTvQ0WWhM-CTNaY4oLiy5k7 This is a playlist of videos by izaw smash. i would suggest watching part one through part 4 (part 3-4 probably being the more important ones, if you already know the basics.)
https://www.youtube.com/watch?v=OYWXCTKKDV0
https://www.youtube.com/watch?v=tqPn3f7Wjk8
https://www.youtube.com/watch?v=uvTrJo3DNog
https://www.youtube.com/watch?v=PBTraLrWAKs
These next 4 are videos by rush hour smash, constituting difference aspects of the game at a high level. very good for grasping a solid understanding of all phases of the game.
https://www.youtube.com/watch?v=YAOOHuozKNU
good vid by beefy smash doods on how to improve. overall, all the channels are very good, and will help you improve as a player.
now, for improving your character.
https://www.youtube.com/watch?v=3DxLNCN6YWg
good for getting a great understanding on what little mac is truly capable of, and seeing what the character can do, and good explanations on his moveset.
https://www.youtube.com/watch?v=Q5pgw0PTWyA (Sol)
https://www.youtube.com/watch?v=dQxHvT1e_eg (Destany)
https://www.youtube.com/watch?v=0PFa0Sg_BTQ (Vash)
https://www.youtube.com/watch?v=P9oQk7jkwaQ (duffo)
https://www.youtube.com/watch?v=STowYkacHDA (ZekkenB)
https://www.youtube.com/watch?v=TLAD6TockFQ (TG Senpai aka your truly :D)
up above are some vids of different top mac mains around the world. as you can see, they have different playstyles and niches about them, give them a watch and see which one you like best.
also, we have a discord channel that is very active and has mac mains from around the world on there (including the ones i listed, and myself). the best place to continue to get tips and stuff.
As for the coaching bit. I will offer this. my time is limited and i do work and attend a lot of things, but i do have a 3ds and am willing to help get you off the ground and get started. just let me know. Good luck dude, mac nation is here to welcome you into the fold.