Geometric tolerancing an assembly of two pieces

Hi,

I would like some help with geometric tolerancing as I am quite new to working with solidworks.

I have an assembly (see picture: assembly) where two pieces (disc and a flange (see picture: project)) of this assembly needs geometric tolerancing. I have tried my best to put some geometric tolerances on the disc, but did not succeed with putting a "position" that is integrated with my dimensions (see picture: disc with tolerances).

I would highly appreciate it if someone could tell me how I can put a position as seen in picture (disc: example).

As for my flange, I have no idea to where to start. Do I start by putting datums, in this case, where should every datum be placed so that the disc fits? What are the main things that I need to think about when putting tolerances?

Thank you in advance for helping a student out !

Naka

SolidworksMbd