I learned the basics as a kid, just like how the pieces move and what is legal. I don't feel like I have ever managed to develop a sense of strategy, and I both think that I need to think for too long about each move, but also still make obvious mistakes like not noticing a threat and losing a piece for no gain.

What would be the best way for a player of my level to improve? Read a book about openings? Follow through games by great players? Obviously part of it will be play lots of chess, is there a particularly good website/app for this? Is playing against humans better than bots?

I'm not likely to have access to much in person games like a club or anything, this would be something in looking to do in my spare time, as and when possible.