Homonyms aren't exclusive to English. For example, a tree has bark, and dogs also bark. I can have a kind of car, I can also have a kind sister. There are many more examples just in English, and Norwegian is bound to have plenty more as well. We just need to learn the context and how to differentiate.
Hundreds, maybe even more.
Luckily, you're not going to need to know all of them, and some have literal English translations which make them freebies if you know the words they're made up of:
å gi opp = to give up
å kaste opp = to throw up
å se ned på = to look down on
å banke opp = to beat up
å tenke gjennom = to think through
Many of our phrasal verbs are adopted from German, so those who know a bit of German or Dutch get some additional help. Examples can be found in this thread.