As already stated, most of the people at a gym are there to get their workout done and go. We're not there to mingle, have a fashion show, or be snooty to the newbies. Chances are good that you won't be the only unfit person there, but when you stick with it, you won't be unfit...
Unless you're thinking about the few introverted machine junkies, most of the regulars will notice you - but, they won't notice the fact that you are unfit. They'll see you week after week, working on improving yourself. THAT is what they will notice. That is what they will encourage you about.
No need to die on any machine. If you or your friends don't know how to use the machines, talk to the gym staff. You're doing this to get stronger and more fit, not to hurt yourself, so take it easy at first and build from there. Just remember this - Always do your best. Why? Becuase at that moment in time, you aren't capable of more and to do less than your best should be unacceptable to you. Everything else comes in time.
Here's a little anecdote for you and I'll shut up...
In order to keep myself honest with regards to my workouts, I signed up for a winter running race series. Stepping up to the same starting line as some of the "serious" runners can certainly feel intimidating. I feel like a hippo sloshing through a water hole with a bunch of gazelles. But, I'm not there to compete with any of them. I'm there to do my best, to measure myself against what I did the last time. Well in yesterday's race, with about half a mile to go (5k race), my legs were starting to get tired and I pretty much felt like walking. I had badly sprained my ankle a few weeks ago and just didn't know if I had it in me to finish the race running. From out of the blue, one of the guys in the 10k race (2 laps of the course) patted me on the back and gave me some encouraging words as he passed me. As he ran past, I saw that he was wearing an Ironman Lake Placid finishers shirt. That was all I needed to kick my butt in gear and finish strong (well, as strong as I could). Imagine that, someone took the time out of his race to encourage me. In a race!
I guess what I'm trying to say in the long winded way that I do, is that everyone starts at their own beginning. Those who have gone before you know how much effort it takes to not only get the ball rolling, but how much effort it takes to keep it in motion. Most of them are more than willing to encourage you along the way. Once the middle of February comes around and the "resolutionists" have stopped going to the gym, you might be surprised how many new "friends" you make with your fellow gym rats
Go for it. It's one of the best things you can do for yourself and your loved ones.
-Frank