There is alot you can do as far as
SEO goes but to be honest I'm not real sure what your ALLOWED to do with the program you have purchased. The last time I looked at ProStores you where limited on a lot of things and the simple things like start a blog "on a sub-domain" was a added cost. With that said here are a few things you should try and change if you can. Who knows they may have changed what you can and can't do.
1. Remove the styles from your code and put it into a external .css file.
2. Change your favicon.ico. This is your store you need your mark next to the http not theirs
3. Add a meta description and keywords
4. Add title attributes to your text links.
5. start a blog
I had to stop there due to the site went 'Under Maintenance'