I'm an advanced beginner. I don't have internet access as much as I like to, so I'd much rather have a series of chess position FENs that I can put into some free chess engine and then try to play them myself offline. I've tried getting those huge books with bunch of problems for beginners (like "mate in three") but they're heavy to carry around and also I'm still struggling with visualization so I like to have the computer nearby. I've also tried to just play a game against those free chess engines but I find it very difficult to maintain my focus. It's much easier to work 30 minutes on a problem or two, take a break, then do another couple, until it becomes easy enough to visualize.
The sort of problems I have in mind are like the one I just mentioned (mate in X number of moves) but also ones see on the popular chess websites, like being given a position and try to either gain material or checkmate or prevent opponent from doing so. In short, not so much positional chess than tactical.
Appreciate suggestions.