Why can't I destroy blocks in minecraft in single player mode?
Why can’t I destroy blocks in Minecraft Single-Player?
I started playing Minecraft a few days ago, and I found that neither left click nor right click seemed to break blocks, so I can't break any blocks!
You must not be in Adventure Mode, which you would have set when you started a game. Check in a new game in survival or creative mode to check that it's not this.
Clicking does not break (many) blocks, you need to click and hold. Initially only a few block types can be feasibly broken using only your hand, including dirt/grass, sand, wood and leaves, so try left-clicking and holding and see if you can break these types of blocks.
Once you've got yourself some wooden tools, you can break stone and make stone tools, etc. which will break blocks faster.