Trust the process. Making a game is a marathon, not a sprint. Start with a smaller project, say a game that you can make in a week. Focus on making the gameplay intriguing and rewarding.
No feature is perfect at first. Go through all the possibilities of a selected feature, and build it in a way that it can be fairly easily altered or expanded.
Learn how to use version control, like GIT or GitHub. Even if you work on a project alone, it can save you in a situation where your project or files get lost or corrupted. It's also a good way for you to keep track of your progress. If you work on a team, make sure that everyone is willing to use version control and help them understand why it's useful.
If you're planning on publishing your game on Steam, it's best to start generating wishlists from early on. Build your game in a way that you can get some sort of marketable material out of it as quickly as possible. You should also give some updates on your developing journey from time to time on different social media platforms. You never know if one of those posts goes viral one day. It's also recommended to take part in all kinds of game-related events. There you can meet new people, grow your network, and show your project to others.
Game making is a fun hobby but a tough job. You have to keep on believing in your project and push it through, no matter what.
False Hope on Steam