Welcome to the UrBackup community. As you are discovering, UrBackup is different, and spending time here reading the posts will no doubt be useful.
From your description, you don’t need any archiving, and I recommend deleting the archive entries you described. UrBackup always keeps as many backups as possible within the limits of available storage and the backup settings for each client. UrBackup storage is very efficient, so please start with the default settings and only change things after you know how your particular mix of clients are behaving.
For the second part, see this answer to a previous post. Many such questions have been asked and answered, and these forums have a good search feature.