Know Nothing About Desktop PC, Need to Handle 3D Modeling and Rendering. AS SMALL AS POSSIBLE

Like I said, know NOTHING about Desktop PC, been using an Inspiron 15 with 12700H and IrisXe with 16G Memory that I got for school stuff.

All my friends jumped off a bridge when they saw that setup /j.

Please spoon-feed me about the whole thing, I know small motherboard is not a common thing, I also heard that I need a good PSU to support everything in my case, no need for any cosmetic BS.

Thanks guys.