You don't have to be a bodybuilder, anyone wanting to gain some fat &/or lose some fat or even just interested are pretty welcome. From a vegan point of view looking the best you can is probably the best advert you can have for being vegan. Let's face it if people think you go vegan & look ace you'll get more people interested in the lifestyle.
The reason we first started the site was actually an off-shoot of the Brighton Animal Rights Campaign website when I first started training & wondering if there were any vegans who lifted or I was the only one in the world
We actually ended up getting more people asking about training than the group
so we started a separate site, then started this forum quite recently.
If you want to add some muscle mass it's pretty easy. For just a recreational lifter who's doing it for health you'd need to add some food (unless you are already overweight, then start moving towards a sensible dietary plan). Say you are eating 3 meals right now (Breakfast, dinner, tea), simply add in a couple of snacks like a bag of nuts or a sandwich mid-morning & mid afternoon. You can start at home doing bodyweight stuff 3 times a week doing push-ups, get a cheap doorway chin-up bar & do negative pull-ups (that is use a chair to get up there, then slowly lower yourself under control), some bodyweight squats or lunges. Depending on your age & health level I'd also include some cardio as well you can do a bit of jogging, or once you get going include some sprinting if you like. Once you get going you can join a gym or buy some dumbbells if you prefer home training & carry on from there.
It's really simple & for 30 minutes a few times a week you can look a whole lot better & if you're campaigning it's much better to look fit & healthy as it puts across the right message about the diet.
If you need any help at all I'd be happy to help you out starting off. Just think about what you want to achieve, whether that be fat loss, muscle gain or whatever & we can easily knock you up a quick training plan to get you into shape for summer time