This is a very common beginner question. We had the same debate for a long time. I thought that it would be best to try with strangers who can be easily kept at a distance and scrubbed out of your life, she felt more comfortable finding someone we knew. I was wary of drama.
I think most people here will tell you that converting vanilla friends is a high-risk activity, and single males in the lifestyle also have an unfortunate reputation, in part because they're often just desperate vanilla males who are single for a reason. People make it weird, gossip, catch feelings, etc. They may or may not have the skills to be cool about it if you can't easily cut them off after.
In our case, we ended up having our first experience with a couple we knew personally, long-time friends of hers and somewhat removed from our life, who turned out to already be familiar with swinging. It was very good luck.