I'm working on a membership site and have activated

I'm working on a membership site and have activated a number of plugins (with the Nelo theme) including Affiliate, Comments Plus, Q&A, Dashboard, and Membership-

When I went to the site, it took well over a minute to load, and I don't even have content yet. What can I do about this?

(I've heard I shouldn't use something like website cache with the membership plugin, is that correct? Also, is that the best thing for speed?)