How many times should we post?

Starting out, I would say posting once a day at most and leaving meaningful comments on as many other people's posts as you can will be the best. To get anywhere, you need to build an audience, and until you have people who follow your posts regularly, you will need to go out and find them on their own posts.

I would suggest looking in the tags that most interest you and reading what others are talking about and then commenting on their posts and with others. Doing so will also provide a chance for those comments to be upvoted, thought that might not happen very often.

A word of caution. The introduceyourself tag is generally meant to be used once. Just so you don't get in trouble, I would advise against using it again. I only say it because there are people here who really want to keep that tag for first time introductions.

In the end, you will need to find what works for you as far as how often you post. But it will take time to get eyes on your posts, so you might as well find people you can talk to, join a community, etc., while you are at. Good luck.