Hi Charlene!
I'm not an illustrator (by any stretch of the imagination
), but I do write picture books and because of it, I usually think in pictures. I think your questions can be answered in a few ways:
1) It's my understanding that illustrators work hard at their craft to build portfolios and do what they can to get their work in front of editors (you should look through the Illustration board to get ideas on how to do that, or perhaps an illustrator here will chime in), who then might show interest, and, at some point, perhaps pair you with a writer on a suitable project. So, yes, to your first question. Making nice pictures is good. Making awesome pictures is even better.
2) It is possible to tell a story entirely through pictures, though it is a challenge. In this case, you would not need a writer. (To answer your second question.)
3) If you want to find a writer to co-create with, do so. But in that case you'd be limited to self-publishing, as traditional publishers find illustrators for picture book manuscripts they acquire; I suspect it's only rarely (and perhaps celebrity or niche) that they'd acquire a team.
As far as having no kids, well, that's not really an issue. However, the bigger question you might ask yourself is: Why do I want to write for kids? Why do I want to write *this* story for kids? If you have friends with kids, spend some time with them. But, better yet, spend some time in the library and read picture books that have been published in the last 5 years. Read about 100 of them. Pay attention to which are written and illustrated by the same person, and which are not, and get to know what publishers -- and kids -- are looking for.
The other thing to do is write the story! Get some feedback on it -- we have a section for critiques here -- or you can find someone to swap manuscripts with -- we have a board for that as well -- or find a critique group to work with regularly (yes, we have a board for that too!). Build confidence in your writing!
I hope any of that helps! Good luck!