World Press / Simple Press SEO HELP

I am new to WP. We recently had someone create a WP site for us using Simple Press. Our site is a support forum for those touched by autism. I want to focus on SEO in order to grow our membership. From our Dashboard the only area I see to work the SEO is under WooThemes. I understand SEO and how the rankings are derived, but I am completely in the dark with WP / SP and what SEO plug-in works best to at least set the foundation.

I greatly appreciate any of your advice in advance.

Thank you!