I struggle to even understand those problems, I checked a lot of 1000-1200 graphs tasks, and I just don't understand them. https://codeforces.me/problemset/problem/2078/B
and the solution for that issue it is not understable for me.
https://codeforces.me/problemset/problem/217/A
A lot of the times, I read the problem, I don't understand fully the problem, the only problem I solved in that range is this one. not sure why it is 1100 https://codeforces.me/contest/1829/problem/E
I can say you that before 1500 there are no any graph tasks (maybe dfs on 1300-1400 rarely). If you see tag "graphs" at 800-1200 it's doesn't mean that you need to observe it as graph. In 99% cases this is math problem or constructive.
It's maybe foolish to say, but I recommend you to not learn topics that you don't need right now. There are a lot newbies that know segment tree, dsu, fft, but still haven't reached pupil. Because their brain full of disturbing things that they don't need