How similar is Ultimate Spider-Man 2000 to the original TASM?

I wanted to start reading Spider-Man, so I decided to begin with the Ultimate Spider-Man run from 2000. I figured it would be a good starting point because it's shorter and I could get a feel for his origin story, along with meeting important characters like his friends and villains. I'm also curious to see how closely it matches the original version, especially when it comes to how Peter Parker becomes Spider-Man.

Eventually, I want to switch over to reading TASM, but honestly, I don't want to read the first issues made like 70 years ago. I figured I could read US and then jump into one of the Modern TASM storylines, but I don't want to be totally confused on who the characters are.