There are literally so many possibilities to increase site speed, and so many things that can be slowing it down.
Take a look at using a CDN like Cloudflare and/or using a caching plugin like W3 Total Cache.
Keep in mind that you could have the most optimized website in the world, but if your host is slow then your site will still be slow. So, your host may also be a good place to look.
Good luck!
