I want to be a Welsh speaker mostly because I’m a huge nerd for Welsh history/literature/folklore, but also because learning Welsh has proven to be extremely therapeutic.
As for the second question, I can’t really think of any specific thing I hope will happen. I’m American, so practical, realistic scenarios for speaking Welsh do not easily spring to mind (I have plenty of un- and semirealistic ones, though). Honestly, the greatest thing that I’m looking forward to is the feeling of vindication. I’ve spent too much of my life trying to learn the things I thought I “should” learn instead of the things I wanted to learn, and it hasn’t really gotten me anywhere. By contrast, I started learning Welsh because of a personal interest in Welsh history and culture, and also because the language just felt right. Now, I’m not only enjoying myself, I’m also doing a lot better at it than any other language I’ve tried to learn (learners need a genuine interest in order to succeed! Who would have thought?). I feel like the whole process is teaching me to trust my own judgment, and becoming a successful Welsh speaker will only confirm that.