Hello jbjoret,
It sounds as though you're having issues with the performance on your Mac. Getting the performance that's expected is very important. To work towards a resolution there are some great troubleshooting steps listed below.
Start by verifying the Mac is running the latest version. You can find the steps for updating in How to update the software on your Mac. If your Mac is updated, or you continue to have issues after updating you'll want to verify that there isn't an application that's using a large portion of the CPU. If you see an app using a large percentage of the CPU you can force quit the application using the steps in View energy consumption in Activity Monitor on Mac.
You can also run the Apple Diagnostic to confirm that there isn't any hardware issue.
Use Apple Diagnostics to test your Mac
If the diagnostic reports an issue you'll want to contact Apple via the Get Support website.
Have a great day!