I've done odd jobs on upwork in the past and my portfolio and experience are not that great. I found that clients want you to solve their problem/need. It's all about the proposal and how you come across to the client, try not to make it all about you. I know that sounds a little harsh but everyone does it. Hire me I have have xyz years of experience at, I studied at blah blah and so on.
Sometimes that's all the client see on 100's of proposals, you need to target your proposal to the client. Tell them why they should hire you, how your going to solve their problem and ask questions so they know what your talking about. It can make the client think alright this guy is asking me questions he must know what he's on about.
Also a useful tip is to search previous hires and see what the client is called. That way you can put their name in the proposal and grab their attention.