Get my site up to date

I have a Joomla Site and need some minor fixes and upgrades. 1) I have a gallery plug in that is not working. 2) there are some things I want to change in my shopping cart work flow. 3) I see some thing on the bottom of my page that are left from the templet I want to get control over and can not see where that is. 4) I want to add sone videos one of my pages. 5) Fix and update my SEO so my page rancking is higher. 5) add a submit support ticket to my support page. 6) I have some problem and similar problems with my other site. Lastly run any updates needed so my site is up to date.