Ok making your website faster is done by doing a few things before you let the cache try to fix things.
When you just add a speed cache, and have not cleaned up your site, well it just never works right.
Please read before you install your speed cache.
Things to check and do.
.Optimize all images, try not to use large images
.Try not to use large image in header
.Theme must be premium, good clean code
.Social plugins can make site load very slow, must choose the right ones
.Try not to use many plugins
.Try not to use affiliate links banners, images, using redirect,not hosted on your site
.Affiliate banners and Images not hosted by you have to redirect out from your site, slows down site
.Clean out database tables from left over tables from plugins not being used
.Only clean database tables, if you know what your doing, but must be done.
.Optimize database tables after cleaning has been done
.Now test site with tools.pingdom.com no aff link,
After you test site, you can see what is slowing down your site using pingdom
If you did everything right, your site will load super fast, and will not need a cache plugin, but most people still use them, if you decide to use one after this is done, it will be super fast.
WordFence is one of the best to use, comes with built in cache for speed, Enable Wordfence Falcon Engine, and you should see a big change in load times.
Hope this helps everyone