I am on medical marijuana but just got a picc line in from a infection. Can I still smoke my medical marijuana with a picc line?

Yes. Smoking marijuana and having a picc line in have not contraindications. It would be good to know why your are taking the marijuana. It alone could affect your general health but i see no connection to this and the picc line itself. I would discuss this thoroughly with your prescribing doctor.
Discussion. Such information needs to be communicated with your treating physician.