[WiredBlade]

There is https://woorank.com which gives some excellent suggestions on how to make your website not only better for SEO but also faster and much better in many ways. Many of the fixes suggested are easy and can definitely improve SEO ranking. Some of the easy fixes are to ensure that your website has a 404 page, appropriate shortcut icons, title, CSS usage and many more. They do provide explanation for the fixes and how they can be achieved. Also, you don't have to optimize the loading speed for the entire website, but you do have to have very quick above the fold loading so you can defer loading unnecessary javaScript, below the fold images etc to after the page has already loaded.

BTW, you can just use the free version of their offering if you have only 1 website you are trying to optimize.