When Hubby and I as beginning signers first started attending Deaf "events", we started with silent dinners. Expectations at silent dinners are minimal, and people were free to get as involved as they felt comfortable. If nothing else, you could just introduce yourself, eat and observe. Pretty low key.
We "graduated" to local Deaf association meetings and socials. We usually didn't discuss "signing" topics or ask "how to sign" questions. We chatted about the same stuff that everyone chats about; weather, children and grandchildren, traffic, shopping, aches and pains (we were in an older group, heh, heh), TV programs, etc. If the Deaf acquaintance noticed that we didn't grasp something, he/she might spell it or explain a sign, as it popped up in conversation. But no "signing" quizzes or drills.
It also pays to have a good sense of humor. There's always at least one character in the crowd who loves messing with newbie signers' minds. We had an elderly Deaf gentlemen in our group who loved intentionally giving us incorrect signs or double-entendre name signs for a chuckle. Of course, we hearies got wise to him and took any sign "suggestions" from him with a grain of salt.