Where can I find documentations on how to resolve a git conflict properly?

Today I did a git push --force, then I had to create a branch out of the old code, but other times I had to save the files I worked on, delete the local repository, git clone again, then reapply my fixes. I want to at least have a bookmark on how to fix things in the future.

Yes, I've heard about VSCode plugins, that supposed to help. But no, I don't want to use a glorified webpage to do coding, regardless if it's directly tied to Micro$lop, or some of the slop was removed by 3rd parties. I tried KATE once, I cannot go back to some sluggish webpage, which only argument for use at the moment is "but it has plugins".