If you want to become a really good chess player it is essential to play, learn and practice as much as possible, good websites to look at are Lichess.org or chess.com, there are also some very good instructive videos on YouTube, which can help with Openings, Tactics, Middlegame and Endings. Just ask if you need guidance on any of these items.
These topics are typical of what will be covered over a period of weeks, copies of this are available, ask if you would like one.