The magic bands actually order themselves. After you have your MDE account set up with at least your profile, family and friends that may travel with you, and have linked a room reservation and tickets, there will come a point where the account starts telling you that you can customize your Magic Bands and need to do so by a specified date, which will be shown as the date that is a month before your arrival. You can go in to the Magic Bands link and customize the bands, meaning choose colors and put a name on them. Then the bands are sent to you just after one month before the trip.
As to fastpass+, you need to link a ticket number, or receipt number for tickets like APs to be picked up when you get there, to be able to do FP+ and then you can start doing them 60 days from arrival for your trip and you can do all days once you are 60 days out from arrival. FP+'s, unfortunately, take a long time to do. You choose each park you want each day and then get to choose three passes for each guest. You choose among options which usually are between morning passes, afternoon passes, late passes, and some other mixture. Then once the confirmed times come up, you can modify the the times you got but can only do one of the three at a time. Ultimately, if you make numerous individual changes, sometimes changing the same pass more than once, you can actually end up with a sequence of times for the three rides you want that you might find close to what you would consider you actually wanted. Further complicating matters and adding substantial time is when you want those in your group to have different passes from the others for some rides, such as part of the family doing a ride with a height requirement while othes with those below the height requirements are doing another ride. In other words, to make all the initial FP+ choices by just designating three rides, having everyone in your group do the same rides, and accepting one of the options given for any 7 night trip usually takes at least 30 minutes and possibly as much as an hour assuming the system does not crash, which it does often at times. Then if you want to make changes those can take up to many hours to do depending on changes you are trying to make. Once you are satisfied with what you have, you can then change them at any time including up to the day in the park that you have but choices can become more limited the closer you get to your date.