Hey @Galym, welcome to the forum! 
I recommend to first read more about custom components here, I’m sure you’ll find many answers there.
As for placing your component in the “right” place in the pipeline: It really depends on what your component does, what features (produced by other components) it consumes and what features (potentially used by other components) it adds. E.g. if the component is a classifier that uses features creates by some featurisers, it will come in the pipeline after the featurisers.
Let me know if you’ve got any more specific questions