Originally posted by YourUncleDarnel:

I just bought AOE 3 and don't see any manual.

3DE is a remaster, there's no specific manual for this game. One for the original release: https://pdfcoffee.com/age-of-empires-iii-standard-manual-pdf-pdf-free.html
Click on download and wait a moment.

Originally posted by YourUncleDarnel:

How do I learn how to play it?

Start the game and click on Tools -> Tutorial.
After that- play the campaign. And after that practice in skirmish vs easy AI and continue learning the game. In between spend some time in the Home City -> Deck Builder menu and learn the civilizations and shipment cards and experiment with different strategies, while learning the maps, game modes, native tribes, mercenaries and royal house units etc.

Thanks.

I hope I made the right decision getting ver 3.0 after listening to this guy.

https://www.youtube.com/watch?v=L8ocR2uQCz4

if you have discord search for Revnak's (the best player) discord

https://discord.com/servers/house-of-trading-post-1088511149907132549

Here you can find decks, strats and people to play with

Originally posted by YourUncleDarnel:

Thanks.

I hope I made the right decision getting ver 3.0 after listening to this guy.

https://www.youtube.com/watch?v=L8ocR2uQCz4

100% made a good choice.
Also make sure to complete the " Art of War " missions ! They are very usefull to learn about the micro in the game :3