I'm trying to set up my character and I'm new to this. My DM is on vacation, so I'm trying to get it set up and ready, How do I set up the Breath Weapon as an attack? <When you use your breath weapon, each creature in the area of the exhalation must make a saving throw, the type of which is determined by your Draconic ancestry. The DC for this saving throw equals 8 + your Constitution modifier + your proficiency bonus. A creature takes 2d6 damage on a failed save, and half as much damage on a successful one
It would be best to specify which system you are playing and which sheet you are using, people will be able to get you up and running in no time with that information :)
We are using the 5th Edition. How do I know what sheet? Is it SRD5?
If in doubt you can post a screen shot of your sheet, it is likely either the 5e OGL or the 5e Shaped sheet but there is at least one more out there. From your description I'd assume OGL. Thanks for confirming, there will likely be a helpful and knowledgeable community member along shortly... these things are often a race ;)
Set up a new entry in your "Attacks and Spellcasting" section on the first tab of your character sheet to look like this (altering the damage, switching the DEX save to CON, and setting the range as appropriate).