I find it interesting that you even are asking the question. But is this a former professor at the school you transferred from or is this a former professor at your current school?
Since you have a question “if” you should then just email and ask. Ask them if it OK to stop by, If there’s push back then at least you know. My daughter had a professor as a mentor that moved to another college out of state. She’s been great answering questions for my daughter. They had a great relationship when she was a professor at her school.