Script to backup all DBs with unique TimeStamp name and remove old backup files?

Hello I have SQL 2016 and am having problems with the Maintenance Plan Wizard to backup all User DBs and the 3 system DBs (master, msdb, model) and Cleanup task.

Can someone provide me a script that can backup all DBs (including 3 system DBs and ignore DBs that are OFFLINE) with unique TimeStamp names and remove old backup files cleanup task (like older than 4 days) please?

Thanks in advance.