None of these things have to do with Rails or Ruby.
Regardless of which language/framework you choose to learn, you'll still find yourself tackling the above concepts in some form.
If you like Ruby and Rails, learn it. There is no "right" choice. What you choose to learn depends on what you want to do with your skills.
Also, taking the above into account, be aware that what language you start with isn't all that important. In the beginning, you'll likely lack the skills to really understand what the differences mean anyhow. The important thing is that you start somewhere and learn.
Don't follow the "flavor of the month" people. There will always be some hot new language or framework to play with.
Pick something that has a knowledgeable and active community for support and you'll do fine with whatever you choose.