Well, I'm no expert, but water changes are probably a good thing
(Based on your tank parameters). Gravel vacuuming is a good thing too, but I've read that during a tanks initial startup, you want to vacuum as little as possible, because the beneficial bacteria, are trying to build up to appropriate levels, and your substrate is one place where they reside.
I would do weekly 20-25% WC's unless your parameters warrant more frequent WC's.
I'm not sure how long you should wait before vacuuming, I waited about a month with no serious issues (during my tanks initial set-up, now I vacuum bi-weekly), but I made sure there wasn't any excess food reaching the bottom, and if it did I cleaned it up.