Welcome!! If staying at one of the Disney resorts, you are able to make FPP’s 60 days out from arrival, which for you would be April 27th. That means the night of April 26th, at either midnight, or regular MK park closing time (whichever is later), you should be ready to hop on and make your reservations. If staying on site, you will be able to book your entire trip’s worth of FPP’s (up to the number of days of park tickets that you have) all in one sitting.
If you’re staying offsite, then it’s slightly different. You will be able to make your FPP’s 30 days out at midnight, but only for the day that’s 30 days away from the day you want the FPP’s for. That means that each night, you’ll have to stay up and book them, for one day at a time.
Hope that makes sense, let us know if you’re staying onsite or offsite and then that’ll help narrow down which option applies to you