Knowing a rabbit's age is really important for knowing what and how much to feed. From your past posts, it appears that your first rabbit is about 6 months of age (got her in March but had been weaned early). That is just about an adult. The 2nd rabbit looks like it is barely over 2 months (got her in June but her eyes were still closed).
This means that both rabbits should be on different diets.
The older one can be on an adult diet:
unlimited hay (not alfalfa)
greens (gradually introduced)
1/4 cup of pellets
The younger one should be on a juvenile diet:
unlimited hay (alfalfa is ok, or any other hay)
daily pellets
no greens yet if she hasn't had them before. Wait until she's 3 months of age before introducing greens.
Their pellets can be different also. The pellets you have, are they plain or do they have colorful bits or seeds in them?
Take a click
here to see a diet overview. You said you have no idea what you're doing, so that should help immensely.
There are also suggestions for healthy brands of pellets. The good brands will have a juvenile version and an adult version.
Aki is correct. No "store bought" treats. They are just crap. The older one, once he's used to greens, can have small treats as suggested at the link. I wouldn't give the baby any treats. They can only mess with her GI system.