Edit custom appointment form on my html website (Database / PHP / JS)

Hello, i have an appointment form on my website. It was made custom for me with several simple functions. i need somebody who can edit this and make changements on it in the future. So I am looking for a long time relation partnership. If you are interested i can send you the link to my webiste and you can check all details, how it is made and how it is working, so you can tell me if you are able to edit it and understand the programming of the freelancer who worked with me before.

Best regards