Improve SEO, website speed and checkout

We need optimize SEO web on desktop and mobile devices, improve the traffic around 13k or 15k, ande the authority score to 25 o 28 position (www.semrush.com), also we should optimize all the loading and speed metrics of our website (www.sabway.es), also improve the loading speed when adding products to the shopping cart, discount coupons and also when continuing the purchase process until it is completed (see PDF document).

Please note that our website uses the Cloudflare service to prevent attacks and improve loading by using the cache on Cloudflare servers. If anyone interested in this project would like to open the website, please let me know your IP address in case I cannot access it.