How do I test that my SPF and DKIM settings is done correctly?

Go to Settings Tab. Click on the gear icon on the right top, on the left side you will see "Sending domains". Click on it.
Click on test button in Action column of that particular domain. It will Test and displays result as Valid if all records added correctly and Invalid if there is a some issue. Mostly when you add these records first time into your DNS hosting panel, it takes some time to propagate all over internet. So for some time (maximum time to propagate is 24 hours) sending domain Test may return result as Invalid status.