Online Dating

So... I met this guy on a dating app (I was bored one night and thought why not lol). And we have spent a total of 7 1/2 hours over two phone calls just talking about literally everything. He is the most down-to-earth, mature sounding guy that I have ever "met" (probably because he's 27 and I'm 19 turning 20 this year). And he's very ambitious and intelligent. I want to skype and meet him eventually, but do you ladies have any opinions or advice concerning this? I know that I should be safe, don't get into his car until you really know him, meet in public areas... but what else?