The steps to getting an ASN essentially entail setting up some objects over at the RIPE database and then letting us know what these are, we will then send you some paperwork to print, sign & return to us. From here, we submit this application to RIPE (along with company documents, if applying as a company) and they will then request ID verification from you directly (if applying as an individual) or seek to validate your Company, if applying as a company. A few days later, RIPE will give you an ASN. This is the short version but it is essentially just a bit of paperwork and that's all.
The /48 is PA space we give to you in order for you to announce via BGP, with your fresh new ASN. This is included for the life of your ASN (or the heat death of the universe, whichever comes first) and you are free to take that and announce it wherever you want. We do make a polite request that you peer with us but it's not a requirement. If you do peer with us we can help get you up & running and your prefix announced.
Hope that helps a little & if not, feel free to find me on Discord (link is in the footer of the website) and I'll be happy to walk you through it.