What should I do if no one answers my question?
First, make sure you’ve asked a good question. To get better answers, you may need to put additional effort into your question. Edit your question to provide status and progress updates. Document your own continued efforts to answer your question. This will naturally bump your question to the homepage and get more people interested in it.
If, despite your best efforts, you feel questions aren’t getting good answers, you can help by offering a bounty on any question more than two days old.
Basically that's what you can do.
That's not so hard to gather the 75 reputation for the set bounty privilege. But if you feel that you are not capable to gather that rep in this site, because you feel you are not an expert in these fields then you have still at least 2 choices to gather that rep:
Edit some badly formatted, or wrongly written posts and correct them. You can get +2 rep for this if your edit is valuable and accepted.
Or what maybe easier to go to a stackexchange site of which topic you are an expert and gather 200 rep there. If you do so, you will automatically get 100 rep on every stackexchange site.
Or if you have a friend who has enough reputation on this site, you can ask him to set a bounty on your question.