Website back end integrations

Hello! I have a web design on my domain already (built in hostinger) . I need a few integrations and touch ups tp make it functional . code can be edited straight hostinger (or imported dont mind) .. it is a one property holiday let so I need calendar integration , payment s integrations and a few buttons to make life and touch ups like this . also to be able to edit the page myself when details change (contact details pictures, copy, etc). Thank you!