Hello,
We are glad to hear that our comversation is helpful for you 🙂
1) One of the best cache plugins is WPRocket but it’s paid extention. W3 Total cache (free plugin) also is not bad. You may try.
To test site speed you can use https://tools.pingdom.com/ or https://gtmetrix.com
2) We still don’t see any problem with that page https://gyazo.com/cdc5a40e3d01b821d224ca9a8f1a5e37
Did you try to check the home page using another browser and another PC? Maybe you have some extention that blocks that image.
Regards