Is studying positional chess necessary?

I just found out my chess.com of 1500 is about 1100 USCF. Should I spend all my time on tactics? I was hoping to read "Simple Chess" by Stean.

If you want to read it go ahead. If you don't get it, save it for later. I assume you just play chess for fun and naturally want to get better, but there is no rush and you should do what gives you enjoyment first. If simply getting better than you were before is all you enjoy than you should probably wait on it.

The meat of your study should be books/videos/articles on the middlegame, endgame and openings accompinied by daily tactics.

A typical day studying should look like this

30-40 % Tactic puzzles

70-60% Reading a book, going over master games, watching videos etc

2-5 Games on CHESScom, ICC, PlayChess etc, lightly analyze afterwards

This is how I go about improving at chess.

I have Simple Chess by stean and I think it's a great book (thin at about 150 pages, but the content is good).  Don't be fooled by the title though.  I don't know what 1500 turn based is, but if it's really 1100 USCF then you may not find the book as useful as, say, "Logical Chess Move by Move" by Chernev or "Understanding Chess Move by Move" by Nunn

Simple Chess is a great book!  I have gone through it twice and it prepared me for Silman's, The Amateur's Mind.  (also a great book!)

Another good book that is a little simpler than Nunn's, Understanding Chess is:

50 Essential Chess Lessons by Steve Giddens.

Great games collection focusing on certain positional aspects.  Very prose heavy with just enough variations.  It is a GREAT book to read after going throught the Silman book mentioned above.