do I post my questions on other posts in the form of an answer?
Posting questions (or comments) as answers to existing posts will get them deleted as "Not an Answer", and if you do this enough and get enough posts flagged/deleted you will end up getting autobanned from posting answers by the system until you can show a certain amount of positive contributions (not readily known by the system, so I can't give any further insights here).
Answers should be reserved for answers to the original question being asked, not for 'comments' on other posts or the question itself.
I find a post, I go to ask for more detail and I'm blocked because I don't have 50 reputation.
By this, you mean "Ask for clarification from a poster". This is called commenting on a post. And this requires 50 reputation points.
You can post a new question but then you're told its too similar to another post.
You can only post a new question similar to but different from the original question if the question is in fact the same exact problem but the answers did not work, or in the case where you can justify that your question is not the identical question already asked elsewhere.
The problem you have is you want to get clarification from the poster of either the question or one of the answers. You cannot do this without 50 reputation points.
This requirement is explained more here: Why are you only allowed to comment with 50 rep?