Just copy pasting my tips in here because I think the first wave is quite difficult for new players but it's quite easy once you know how to start out:
Tips:
- If you have nothing else selected, you can right click to move the war machine, move it close to metal and gas at the start as you need these the most
- Put your first miners on metal and gas to help build more miners
- Try to get to your miner limit as soon as possible, this starts at 20 and can go up to 35
- Before the first enemy wave comes you should aim to have built a beam frigate or missile frigate and 4-5 fighters
- The first wave is quite difficult until you figure out how to start and then it becomes a lot easier