Of these, 1: Chose the project you want to contribute to (and 1.5: Choose the issue to work on) and 9: Follow up are the hard ones. Both are primarily social problems.

For 1, it's mostly about knowing yourself. What projects interest you, and where can you contribute?

For 9, it's convincing the owners that your contribution is a net positive. Start with 2: Check out how to contribute, and proactively reach out so your pull request doesn't come out of the blue.

Oh, and be willing to put your ego aside -- it can be tough to defend your work, particularly if you're a new (and thus haven't built up trust) contributor. It gets easier, both as the project learns to trust you and as you learn the work within their practices.