Optimize or redo or my web site

Web site should be mobile compatible, fast loading, SEO optimized, ready to ads campaign (Google, Facebook, etc). It should be simple, straightforward, easy to modify. I am a computer scientist, but do not have the time to optimizes myself the web, but I would be involved in all step, and and closely be assisted, because I want to LEARN these stuffs.
I am in a niche of “mathematical modeling” and have lot of free stuff to offer, as well as some paid stuff.