I have done what you want to do now. I have earned a nice amount, with a very good research and experience and of course I got lucky. But when I think of it now, if things got turned in the other way it would be bad, very bad. Don't do it on the edge and invest in more different things. I don't know about those coins that you are mentioned. It is not my first pick for sure.
Yes that is a good decision, if a person do not have enough money to invest or to do trading with, first he should earn money, and i think even this forum is providing good opportunities to people to earn money from here, but i think that there always remain good competition therefore you need to have good skill for making room for yourself.