I am going to try to give you some advice based on my experience earning rep, as a non-professional end user.
First, you can earn a thousand rep (while under two thousand total) just for suggesting edits to posts. This is a slow but easy way to get going.
When looking for something to answer, I don't set out to find something that I already know the answer to. I look for something I find interesting, perhaps something I would like to know the answer to myself.
Once you find something you are interested in, the next step is to leave comments for the OP, to get any extra information you may need, for example, a version number or a command they ran.
Once you have that, assuming you don't know an answer already, visit relevant sites or other network sites, repos, bug reports, even just Google results you can find that are on the subject and through this research you can build an answer, even if you do not have perfect knowledge of the subject.
This can be a bit of a time sink at first but as you build knowledge by answering and failing to answer questions, you will start to see patterns that repeat in seemingly very different questions and others will seem trivial.
Another important factor in an answer is formatting, well-formatted answers receive upvotes.
code looks like this
links look like this
KB Keys look like this
16.04 tags look like this
Don't forget paragraphs, basic grammar and be nice.
These are the basic things I do when answering questions but it is mostly going to take effort on your part to make any real rep from answers, if you feel overwhelmed, take it one question at a time, read and research until you feel comfortable and it is OK to be wrong, everyone is wrong sometimes, you can change or remove wrong answers later.
Some useful links to get you started:
Useful meta posts:
Everyone feel free to add more useful links :)