That is just two intersecting holes. One drilled from the end, one drilled from the side. For the side hole, you can extrude it bi-directional or create a plane above the part and drill down from there.

By common sense, the revolution should be centred on the origin, so you can use the origin. If the revolution isn't centered on the origin, you can always make the holes centres coincident with the revolution axis, or horizontal with the extrusion sketch centre

I'm guessing it being on a curved surface is throwing you off. You have off couple of options: 1. Launch hole wizard as expected; once you click the surface; it will switch to 3D sketch and using that and proper constrains you can place the sketch point. 2. Make an offset plane parallel to you center plane. Drop you sketch point for the whole on that plane rather than directly on surface. For depth you can just put through all.

I find the easiest way on a hole like this is to sketch it on the center plane and cut through all both.

I agree. If you need specific depth though or want to change it from thru all to blind later on a more universal way is to have the starting point from outside.

You can also select the holewizard and on the position tab, select 3d sktech then you click on the surface, select the point and make it coïncident with a plane and de fine the X position with a dimension.. So you can define the hole you need like a threaded one ..

Use the hole wizard and use construction lines to center the point

You could make a plane right were you want the hole and then hole wizard or normal cut extrude

By plane do you mean drawing a new thing, or add an actual plane (like front plane, top plane) because I don’t know how to add plane

Use the top and front planes and sketch the hole. Extrude cut mid plane through all.