"Best" practice for new webhost

Hope everybody is doing super on this fine sunny day (in Sweden).

My question is. I have my current webhost at one.com and have been there for last 10 years.

Now i want to move to another webhost which offers CDN, SSD storages and support of FTP transfer from website to i.e a NAS. My current host do not support i.e that i take backup from Snapshot Pro and send it directly to my NAS. They have restriction in their php setup.

So i NEVER done this before. What should i do in terms of ensuring the transfer goes as smoothly and secure as possible. Backups? Whatever needed. Please advice.

Br Hamid