JustShiney - I work in a thoroughly male dominated area and there are quite a few women doing trades like mechanical fitters, industrial sparkies etc that seem to really be enjoying it and making a go of it.
I think if I was you and was worried about feeling insecure being among so many blokes, try getting an apprenticeship with a larger company (e.g. bigger mining/manufacturing company) instead of a small employer. Try to find one where you know there are already a few happy female apprentices. It is a generalisation and I have butted heads plenty of times with fossilised dinosaur man-relics even in the big company I work for, but the big companies seem to have HR and diversity people watching carefully and making sure the opportunities support everyone equally.
I wont lie, there will likely still be the creepy staring at first which is a bit annoying (seriously no tickets on myself here, I don't get how ANYONE can look vaguely attractive in sweaty high viz gear!), but once you get to know everyone and prove you're a good hard worker with a good attitude, they tend to respect you for being a good worker and the creepiness goes away.
Seriously, I would not let these sorts of things bother you, the reality in the field is actually a lot better than most people might assume. I'd go for it!