Feed the existing roses now. Wait until the new roses have had a chance to settle in; they should quickly produce some new growth. Then feed them!

For the existing roses you can apply the diluted fish-e around the edge of the canopy; no need to reach under the canes. For the new roses water the root ball area initially, since they have no feeder roots yet.

Thank you for the advice. Also do you need to pull back mulch when you use it like granular so or can you pour over mulch?

IMO Alaska fish fertilizer is expensive and over-hyped, you can buy cheaper liquid fertilizer with more NPK. As for the mulch, leave it alone and pour the fertilizer on top.

FYI: fast release nitrogen only lasts in the root zone for about two weeks while granular(slow release) will continue to feed for three months.

As this is the first time I've fertilized them and some of them were just planted I wanted to use something that had less chance to burn with a little more room for error as I'm completely new at roses. I thought about trying a granular next year when I'm a little more comfortable with what I'm doing. It wasn't really that expensive. What other liquid fertilizers do you recommend?

It's true you should only use liquid the first year but you can dilute Miracle Gro fast release(1/3 strength), if you can get a good price on fish fertilizer then by all means use it.