Most smart phones can make fairly decent videos, provided you're in enough light (luckily, the sun is a marvelous source of light!), so if you want to vlog, and you already have a newer smartphone, start with that.
The best camera is the one you have with you. If you want to vlog, then make sure you're ready to record anytime anything interesting happens, or anytime you feel inspired to start talking or connecting with your audience.
I've found a lot of vloggers just lose steam after a few weeks or months, so make sure you know what your pace will be so you don't burn out too quickly, and what your focus is, so it's not just another person filming themselves going to the mall or doing, say, yet another set of store hauls that we've seen from tons of other vloggers.