I know that feeling but while coding may look like something you have to spend a life long time to learn, its not true. I started using Unity not long ago and stopped the online course in 50% of it.
As you saw I cold make a game and submit it to a Jam, so I believe you are able to do the same. Just take your time to learn things before starting for real, thats what I would say. Also, if you think Unity is too hard there are visual script engines like Construct, ClickTeam Fusion, G-develop and others.
