I'm still very new to SolidWorks and need some assistance on how to create a part.  I need to create a cylinder that has one end closed (capped).  I am able to create a cylinder by drawing two circles of the correct radius and then doing an extrude to the correct length.  However, this makes a completely hollow cylinder and doesn't leave one end of it solid.  I'd need to leave one end about 2mm thick (solid).  How do I do this when doing an extrude?

The next part is I need to create 2 slits in the cylinder about .5mm wide from the open end down about 10mm.

Here is a picture of what I'm trying to achieve (only this one is slightly larger than what I want to design).

https://www.thingiverse.com/thing:1675311

Any help and examples would be greatly appreciated!

Kind Regards,

Nelson