Might want to consider a proxy workflow.
Post comp spec and kind of footage used.
I'm working on a macbook pro. 2,4 GHz Intel Core i5, 8 GB 1600MHz DDR3, Intel Iris 1536 MB
The footage is a vertical video, shot with iPhone. .MOV 2160x3840 23,38 GB
How do I set a proxy workflow? I tried something with proxy settings which didn't work
That is a very slow, low-core CPU, with the bare minimum RAM for PrPro to operate. And you're throwing 4k long-GOP media at it, the nastiest stuff for CPU/cores/threads/RAM made.
Yea, you will have to use proxies on that rig ... but then, even on many rigs with a lot more ooomph, you'd still need proxies for that media.