Hi i would like to say you allready got tons of good advices ,i wanted just to add ,i wouldnt focus too much on the rating (it means nothing here i would say) , i lost years here by counting on the engines too show me my mistakes they show you the strongest moves but if you dont understand them (often my case ) then its useless ,i now find the ideas i missed by using a good database (a database where you got good club players in example with junior shampionship games are fine ,Masters avoiding most of the tactics so you dont see the ideas , so i got a database with club players and i can sort them by number of moves i look at the shortest and i see most of the tactics ideas in the opening).
I am 51 and i am litterally blind when i play blitz so for the moment i try visualisations exercises wiht tactics training
And I at 725 and wondering if some tlinteractive books are enough. That said. Ii have only been at this since mid October....