I second the recommendation of a PLB (Personal Locator Beacon). An EPIRB is the best, but we have an ACR ResQLink beacon. I also have a floating and waterproof handheld radio. On excursions offshore, I assemble everything into a ditch bag. I don't have a raft, but like some safety items, seems excessive until you need it! I haven't bought one mostly because they are expensive and take storage space. For life jackets, I have 12 on board, including two for kids. That covers me for the max I'll ever have on board, and to my surprise, parents seem to show up with no life jackets for their own kids. I have 4 of the inflatable-type life jackets, which are great because they don't take up as much space. I have the ones from West Marine called "Coastal." They auto-inflate if you hit the water. These are great when you have inexperienced guests. If somebody doesn't seem confident in their answer of knowing how to swim, they always get a life jacket. Also, we always put one on when going on the bow at night.
As for training, the idea of the captain is great. Also, there are likely courses taught somewhere there, so look for those. You'll want courses like twin screw handling, navigation, and Radar. One more thing is to be in charge as the Captain of your boat. Don't let people do things that endanger your boat and guests. You're responsible for everybody's safety, so keep that in mind. I make sure that my immediate family all knows how to operate the radio, the PLB, and the basics of the boat. They always complain and say they know already, but I don't think they do. Probably an old military thing for me, but we practice it!
