This map is not shrouded, and as such it is easy to decide how many units you will need to cover the map in the fastest possible way. What many players will do is have a unit going from the start to a city, then to another city, and then to the next, possibly not using the direct route, and often running out of supplies on the way. If you are able to save some travel time, use multiple units, one going to city A, one to city B, another to city C and so on, using the fastest possible approach. Ships on turn 2/3 should never sail with just one unit on board, assuming there are more than one objective to be captured wherever it is going, fill it up with multiple units that you can then drop off at whatever point on the map that lets them get to an objective the fastest.
If we were playing on a shrouded map, the same principles apply, but you would not stop building units on turn 2, you'd repeat (while building some supplies) the build from the first turn several times, maybe ending up with 10 or more ships, and a dozen tiny rifle units spreading out over the map. The ships would drop off a rifle/horse unit every time it reach something looking like a new shore, and then moving on.
You'd have to guess what your starting location is though, sometimes I've ended up with transports on a little lake, since I thought I was starting on a coast, but that cannot be helped, you'll just have to make an estimate of what you need, and start exploring!