FIX bugs in my website x 5

I am the owner of a school. I have five relatively minor issues with my website that I need fixed quite urgently. I should point out that I am very fussy and I understand that being fussy will frustrate some people. Best that I'm upfront. While I am fussy, I appreciate quality work for a fair price. If I connect with the right person on this platform, there will be ongoing work.

Here are the five tasks:

1. Not secure message showing in URL
2. Plug in causing an error - email alert received
3. Website not saving edits as it ordinarily would
4. Website is very, very slow
5. Minor editing to a single page

Here is the website address: www.avse.edu.vn