It can be a hard line to draw with your therapist. Are you friends, colleagues, acquaintances, or something else? Personally I think it is a unique relationship. Very few relationships are all about you but therapy is unique in that way, the client is definitely at the centre of it, our time together is about your challenges and your life. Therapists might share some things but the dynamic should be weighted towards the client. The relationship should be a positive one, and I always hope that my clients know that I care about them and try to make the environment as warm and welcoming as possible. Your therapist should be able to model a healthy dynamic in therapy, with appropriate boundaries.
Can I be friends with my therapist?
It may feel that you are friends with you therapist, that's great that you're comfortable with them. But it should still feel professional, this is someone you're trusting, maybe with some things you've never shared before. Most therapists won't be friends with you, this is to keep the relationship focused on therapy. This may change after a few years but that depends on the therapist.
One thing that can blur this line is if you see each other out and about, your therapist should discuss what will happen in this situation. For example, I will respond to a greeting but that's it. This is how I have decided it is best to keep my client relationships as safe as possible. I wouldn't know who you were with, and remember outside of the therapy room we can't guarantee confidentiality in the same way, we don't know who might overhear us.