Here is a screenshot of the jumping game i wanna make.!
And what are you having trouble with?
Welcome to the community. As mentioned throughout the “How do I” category, making a general thread of “how do I make this game” isn’t really something that we can help out with.
As there is an endless vertical jump example built into the engine already, I’d say review the available resources in the engine itself, the examples page: https://gdevelop-app.com/game-examples-starters/, and the wiki: http://wiki.compilgames.net/doku.php/gdevelop5/
Once you’ve attempted to make what you’re wanting, please feel free to make a thread for a specific question, and the community will do their best to assist if we can.
With the above in mind, I’m closing this thread. Thanks!