I have just started playing with all py Mods and I am already lost finding what recipe is best to use

I want to create iron plates. So far I see the following options:
8 ore -> 1 plate
2 iron oxide -> 1 plate
2 iron oxide + 50 hot air -> 3 plates
So the best thing I can do in my current starting phase is obviously the last one, although its very surprising that hot air needs stone!
This actually results in the recipe requiring 2 iron oxide + 1.43 stone -> 3 plates.
But it gets even worse! I can create iron oxide by using 5 plates + 50 nitrobenzene! I tried calculating the raw ores I need to create 50 nitrobenzene but I got lost very quickly, as it resulted in a huge chain of production steps....
Can anyone help me? Should I create iron oxide or is it a waste of ressources?