I'm not 100% sure about the difference between ha and har since they both mean "to have" (I guess). Any help is highly appreciated :)
Å ha is a verb. Å ha, har, hadde, har hatt. To have a dog. - Å ha en hund. I have a dog. - Jeg har en hund. If you can put "å" in front of it, you have to use "ha". Read more about how to use verbs. :)
Tusen takk! I'm following the app lessons order but I'll accept your advice and have some extra homework as well!