I know that a flyer isn't too difficult to create even for a beginner in this. All you need to do is find a program for graphic design and read more information on specialized portals, you can find many tips and even free examples there, for example, there is a mockup flyer here
https://www.ls.graphics/free-mockups/flyer-mockup , which you can use as a sample. I think that this will help you save your time and you will get a skill in graphic design, maybe it will help you in the future.