Make sure you take your prenatals and that they have iron in then (the gummy ones do not) and extra protein. Nuts have a lot of protein, I eat a lot of trail mix :)
No you don't have to eat meat. But you need to make sure to get your protein and iron still. So yes, talk to someone and get maybe a list of good substitutions!
No, you don't. I have a friend who changed to vegetarian during her last pregnancy and got plenty of protein and everything. Talk to a nutritionist, take supplements, read books, there might also be good websites to help you plan your meals to get the right amount of vitamins and minerals and protein.