not reading the rules, understanding the game at all
looking at the map and seeing nothing and not even hovering the mouse over the empty map hex before walking into it, and you have no idea and lost badly, i'd say you were lucky to survive at all, in real life, they would have followed you back and took your head, so learn from it,
read the manual, watch the other video's online on how to play and learn, then you may enjoy it more, and maybe live somewhat longer
land is never unoccupied, learn the lesson, hovering over the area will tell you how many units should be expected to be defending, and tbh it will be more than you have atm so build before invading, like i said before, this isn't Rome total war, it's a sim more than a game, and without understanding it, you will die often and won't maybe enjoy it, i've still not read the manual, and maybe never will, then again i know the game inside out
my advice is never play online without at least playing every nation first in single player, as each play differently and then you will or should know what to expect from others and play somewhat better and survive online, your approach is maybe some what new so unless you wish to lose a lot and die in every game you play, i'd learn how to play first in single player and then and only then play online and post videos of it
Fist MP as Britanie attacked too early 
Blasted AI!!