I’m in my early 30’s so I can sympathize a bit. I think you should follow po18guy’s advice as well as simply get involved in the community by volunteering and join some sort of young people’s group. I know Singles for Christ which is ran through the organization called Couples for Christ, is a great way to get connected with single Catholics like yourself. Each city has different young people’s groups so you might have to do some investigation by calling your local diocese, asking your priest or you might have to go to a neighboring cities as well. For an instance, there is nothing in my city for single Catholics but the bigger city has everything. An hour drive and I’m connected. You could also try to volunteer somewhere and see where that leads.
The online dating sites are also good. I’ve dabbled a bit with them myself. I suggest that you stick to some of the Christian ones such as Christian Cafe (I’ve met several people who have found their spouses through it), Christianmingle are good ones. The Catholic ones I haven’t yet tried but they seem to be good. Eharmony is also good. I once met someone through that. Things didn’t work out but it was because there was no chemistry. The website did a great job selection wise. He was a great guy.
One of the things I learned about vocations is the importance of prayer, experience and simple trial and error. Sometimes you just need to be willing to ask a girl out for a casual coffee at a Tim Horton’s or a Starbucks. If you are curious about the other vocations, you can always do some research such as interview a few priests of various ages ex someone young as well as someone older, you can look up websites, read some books and visit some orders. Often God reveals his calling through simple experiences. Vocation basically has no age limit.
God knows his plans for us and He knows at what age we will be ready. I recently joined the Catholic church about 9 months ago so don’t let this big step prevent you from exploring and experiencing the wonderful glory of God.