I'm sorry to hear that you were disappointed. I will try to add more guidance in future updates.
1. To interact with a planet, not all regions have planets. You need to reach a star system with stars to find planets. The starting area for players does not contain stars or planets.
2. To remove unwanted parts, for keyboard and mouse players, press the R key, and for controller players, press the A button to delete the part at the cursor's location. This tip is mentioned in the key prompts in the top left corner, perhaps not prominently enough?