Can I delete my photos and music from my MacBook air and have them in the iCloud?

My MacBook Air is full, no room for data or anything else. I have purchased 2TB extra space, but my HD has all the music and photos on it, despite me wanting to have it in iCloud.

Can I safely delete my photos and music from my MacBook air and have them in the Icloud?

I would then have a lot more storage.

In addition, I have Time Machine connected to an external HDD with heaps of space, but I am getting a disk full message for it also.

I have iMazing, and Clean My Mac as well, but I am still unsure how to do this space recovery safely.

Is there a simple step-by-step guide somewhere?

I am nearly 80yo, and this is annoying the bejesus out of me.

[Re-Titled by Moderator]