As a newcomer becoming a worker will take significant time and effort. You need to build trust in your capabilities before people are likely to approve you as a developer.
If you have cryptocurrency already, you can move onto BitShares through a bridge. Otherwise, you could purchase some on a centralized cryptocurrency exchange, or you could earn cryptocurrency directly on the Steem social network (steemit.com). If you're new to cryptocurrency in general and don't want to buy anything yet, I'd recommend starting with Steem.