A few things first:
1. i wouldn't worry about advanced strategy now, i'd focus on the basics, the fundamentals.
2. the main reason you lost that game is that you played somebody far more experienced than you. try to play other newbies if you can, you'll be much more competitive. or if you play experienced players, accept that you're likely going to lose, but do it for the learning experience.
3. a great way to learn is to watch games between good players and see things they're doing that you are not. here is a good one for that, that covers every stage of the game: https://www.warlight.net/MultiPlayer?GameID=11134536
For the game you posted:
You should have stacked to 9 and not lost your first territory. Losing that gives him a huge advantage. When you start out connected it's tricky but there if you stack to 9, you can then pick up a bonus in Antarctica on turn 2 if things go right.
After that, you did a good job expanding and clearing bonuses. Only one game but you seem to have that part down fairly well.
But you made a huge mistake and missed a big opportunity not going hard into Central America. You knew he was there but you went after the South America bonus instead of driving north with all your armies to try and break his bonuses. Big, big mistake. When you lose a territory like that, they have a territory advantage -- but you have an advantage in that you know where they are and they don't know where you are. So you have to try and turn the tables by going in hard and breaking their bonuses. In this case he had everything in North America/Canada, if you had gotten up there, it was game over.
And your combat clearly needs work. This is impossible to just explain for you though. It takes practice. And watching games. But you didn't seem to protect yourself well enough and you made some attacks when it was obvious you would lose them. How to fight effectively is somewhat counterintuitive. A lot of newbies want to play coy and be sorta passive, planning to win later. You can't really do that. The person who wins the early battles usually wins the game. You need to be aggressive and protect yourself well. Here he had already won one battle. If he won the first battle in South America too -- you were toast. You needed to be aggressive there, and at the very least play great defense. You did neither and the game was basically over right there.