ZBF2L is a LOT of cases, do not even think about it before you have tried out VHF2L. From there you can continue and add upp cases if you like the style.
If you only know 2 look OLL = many cases to learn if you like it to become 1 look and if you are thinking of Petrus, then rather learn COLL than the rest of the OLL's.
I suggest this as a wery potentional speedcubing method:
1; 2x2x2
2; 2x2x3
3; Fix bad edges (M' U M style)
4; End F2L but ignore the last FL edge (2-gen)
5; COLL (42 cases)
6; Permute last 5 edges (16 cases)
1-3 is exactly as Petrus, the rest is a more advanced approach than the original method.