I’m trying to make a two islands that will be connected by a bridge or a land bridge I’m wondering for any good tutorials for making a nice map that has a big landscape that will have a town or two on each island because most tutorials are how to make canyons and stuff also any ways to make it look smooth when it gets into unreal engine
Just learn the basics of world machine -> after that you will be abel to create good island landscapes. Otherwise use the landscape tool -> in my opinion pretty good to create island. Therefore just add a water plane + a landscape -> now sculpt the landscape so that it get’s over the water levek 
Like say you , just learn the basics of World Machine, you have all tools you need & make all you will want , spline/line/poly & mask shape etc… for making road , river , island , all you need .But it’s hard ,if you do not know and it’s take a little time before making all you want .
Hey Steven!
Try these videos, they are very good IMHO.