Can anyone tell me how many days in advance I can make some gum paste roses for a cake? And how do I store them until I need them? Thanks a bunch!

At least a month in advance , stored in a cool dry place , not the fridge !!!

You can make and store them way in advance of your decorating. They get hard as a brick. lol!!! I have dummy cakes here that i entered in fairs, they are still beautiful. You can just store them in those plastic drawers, or airtight containers, etc. This will keep the dust off,etc. But making them way in advance is not problem. hth

I just used some that were made a year ago! They were stored properly and look just as good as the day I made them.

Thank you to all who replied. I have another questions as I am an amateur- how much fondant do I need to cover a 14 inch cake?

If it is 14" x 4", you add 14 plus 2x the sides , which would be 8. This is 22" and then add another 2-3 inches. So you would roll out your fondant 24-25" diameter. Whatever the size of the cake. you take the diameter , add twice the highth of the cake, then a couple more inches. Roll it out, drape over your cake, and go from there. Lots of youtube videos on this. hth