which processor do I have

Click on the Apple menu > About This Mac located in the top menu left side.

In addition to what BobTheFisherman has provided you, you can also get more details on which processor your Mac has by doing the following:

1. Hold down the option key, and then, select the Apple logo in the upper left-hand side of the macOS menu bar.
2. Select "System Information."
3. When the System Information pop-up window appears, select "Hardware" and you should be greeted with a Hardware Overview that includes detailed information about your Mac's CPU.

If you also want info about your Mac's graphics processing, just select the "Graphics/Displays" option under the Hardware category.