Hi!
Let me begin with the error message first:
To upload the SQL data we first create a dump file using native SQL functionality and by default we place it in C:\Programdata\CloudBerryLab\CloudBerry Backup\MSSQL. After upload the folder is auto-cleared of these files. It is possible that there's simply currently not enough space for those dump files and the software presents this error message.

You can change that folder via tools > options > advanced > temporary folder.

Regarding the schedule:
You can use predefined default schedule and start making backups on Sunday

That will be sufficient for most SQL configurations.

What if for bare metal backup? and file-level backup?

I'm trying to backup file servers and some virtual machines!

For image-based and file backups it's much simpler.
You just need to enable block-level mode when setting up the plan and on the scheduling screen specify the plan to perform full backups once a week on Sunday.

Here's an example:

If you are running out of disk space, then the first thing I would do is compare the amount of data you are backing up across all computers to the amount of backup storage you have available. Once you have verified that you have sufficient backup storage (the actual amount needed will depend greatly on backup options and type of data being backed up), you can then look more closely at your retention settings (https://www.msp360.com/resources/blog/backup-retention-policies/) These settings determine how many versions of each file (for file backup or images for image backup) are kept in backup storage. As an example, if you set to 10, then CloudBerry will keep up to 10 versions of each file in backup storage. The more versions you keep, the more backup storage you are going to need. Check these settings along with the others (like what to do with deleted files) explained in the blog post to make sure they adhere to what your customers need.

As far as backup types for file and image, there are only two types: Full and Incremental (Differentials do not apply here). The initial file backup is always a Full (everything). After that, file backups are always incremental - meaning we only back up changed files. If you use the Block-Level Backup option, we can back up only the changes within files (this is a good option for large files that have small changes). But, you will then need to schedule full backups for these files using the Full backup schedule option. This option does not do a full backup on everything, like the one initially performed. What it does is perform a full backup of any files that were backed up previously using a block-level incremental. This is needed in order to properly maintain retention settings. You can schedule them as needed (weekly, bi-weekly, monthly).

Thanks a lot for your answers. I think I'm doing right now.