Action Packed 4v4 Tournament! Beyond All Reason (Epic RTS) 

fully agreed

Make sure you have a good grip on your hotkeys so that you slowly get used to pressing them and not using your mouse for most things ! Apart from that, it's going to take time for you to learn the muscle memory to be quick, and to learn to divide your attention so you can keep track of multiple things at once. You'll get there though ! As with most skills it's a lot of repetition and experience.

The website has lots if resources to help you learn. Also I think there are some basic hot keys mapped out in game, in controls or something.

It's a "feel" thing. Give yourself the time and the slack to climb the learning curve of an RTS. Honestly, it's way more about systematically grasping the circumstances of the game then winning or losing. The controls will come with time, and it will feel like playing an instrument. In the beginning, there is nothing wrong with doing things slowly but trying to do them the right way. I'd recommend learning a basic opening for both and a basic opening for vehicles. I prefer to play front line, but whatever position you prefer, stick to that roll. You want to standardize your play experience as much as possible while you are getting a feel for the game. Once you feel like you really have some momentum and the game mastered, then expand on builds and positions to play.

Start with scenario 001. it gives you a purely defensive enemy you can just build stuff against and see what does what. Afterwards, you can do skirmishes against builder AIs who are not totally passive but give you plenty of time to do stuff.

U can pause with the pause-break key. Alt - slows and alt + speeds up the game. Switch to grid optimized under controls, hotkeys, keybindings. It let's u build with keys from Q to V. Other than that it just takes time. U could also watch replays with player perspective.