which ‘project’ bike to take apart/rebuild to learn maintenance as a complete beginner, are these good?

I’m a complete beginner to bike maintenance so I figured it might be a good idea to get a second bike to mess around/make mistakes with while i learn.

[I found these two bikes available locally.](https://imgur.com/a/RAgDfG8) Are either worth it?

1 – A trek 850 for £60

2 – A trek 700 for £75

by CapnJustin