I wouldn't worry so much about upvoting when you're a minnow, though it's a good way to support someone without leaving a message (especially when you may not have the time to leave a lengthy message). Post as much or as little as you are able to, and spend more time worrying about the quality of your posts instead of the quantity. I've had posts that have rewarded me handsomely that were the only thing I've posted in a week. I've had other posts that haven't earned a dime in a week where I posted regularly.

You'll figure it out as you go along. As long as you're thoughtful and considerate and make an effort to engage with other people, you'll find a good groove here. Oh...and always answer the comments on your posts!