I really can't give you an intelligent opinion regarding purchasing steem but the $20/week plan sounds pretty solid/safe.

In regards to creating content I think perhaps if you were to carve yourself a niche' in maybe 2 or 3 subjects at the most that you may well find a solid following within those subjects.

I would also suggest following plenty of others and reading these posts and comment when you have something meaningful to add- even if it's a question- there's lots of interesting stuff written here- and Steemians, I believe, are of above average IQ so there's lots of good content. I hope that helps!