Liz_Atems_elisatems I wouldn't worry about having the internal drive 71% full. With a hard drive, that would be different, as they would slow down as they got full, but with SSDs, you can get a lot closer to full without worry. Also, there are a lot of "rules of thumb" for how much space you should leave free - I've usually seen ~20% mentioned - but even those break down as SSDs get larger; the OS's needs for free space don't go up dramatically with a larger drive.
I have about 10% free on my 2TB internal in my 14" MacBook Pro, with no ill effects whatsoever - well over half of that is photos, my Lightroom catalogs, and a lot of sample-based music data, all of which I've split off into separate volumes sharing the same APFS container as the system volume. I think you'd be fine with 30-50GB free as long as you aren't routinely running out of RAM.