atatransport.com SEO

I need to have a complete overhaul done on this website to make it as attractive as possible for SEO. No major issues that I can think of. The last version of Google updated and really messed up the rankings and did a lot of damage. I had thought that what we had done was alright but apparently Google didn't like the changes we'd made. I need someone to give me a plan of what they will do, how long it will take, and then explain to me what realistic timelines we will have in order to get some results. I am open to suggestions and am looking to only work with real professionals.