You have everything you need to improve here at chess.com. That you are paying for right now. I would not buy a electronic chessboard to improve. I would only buy a e-board if that helps you play better over a 2d screen.
At a ameture level and that is 99.99% of us. Improving your skill comes down to 2 things. Not blundering your pieces. And being able to spot the other players blunders.
Puzzle Rush and game practice is a great way to improve.
I love what software offers nowadays. However being an old school chess player I tend to miss some dangers and commit blunders when on screen. Playing OTB might be helpful IMO.
ChessUp caught my attention as far as instant hints. OTOH I think it may be more distracting than helpful.
Chessnut seems to have upper hand here.
I
Halloo Chess Players
I am looking for a suggestion on buying e-board to polish my chess skills. It is a serious hobby for me, and I have regular private lessons with one of Polish Grandmasters. As I am 51 and prefer some old school approach I think such a e-board might be useful in the process of learning and online playing.
What I like about ChessUp is colourful indications as far as a quality of the moves. As I presume, such instant hints are available during learning, not an online game.
I am not sure if ChessNut Air offers any instant hints, as I understood reviews (also at this forum), that ChessNut Air is just an e-board, so ChessUp seems to be more advanced.
OTH maybe I am dulling myself into believing that ChessUp e-board with its colourful hints for mistakes and best moves would make my learning more efficient.