Hi. You can gain resource by deploying Nebulon B near those grey boxes. It will harvest until 100% full. Then send the transport ship from Nebulon back to the base. You'll need to protect those ships from enemy fighters.
To build ISD or MC80, you need to gain more experience to level up your tech to certain level. Keep destroying enemy unit to gain experience.
For these comment, I have updated the game with some mission levels so that it can be a tutorial to this game. Thanks.