launch Amazon KDP fantasy ebook

I am a published author in technical fields and am somewhat familiar with how "real" publishers launch, but this is my first indie project, and my first fiction book. I obviously don't have a dedicated marketing team like a traditional publisher and want to self publish with Amazon KDP , but have no experience in indie ebook launch. I have a good, edited manuscript / good cover / properly formatted etc., so skip all that part. This is for the launch only, no input on the book content. I do not have a writer's platform, and have barely even begun creating social media accounts for my pen name ( I do my tech writing in my real name and fiction in a pen name.). My budget is somewhat open. I will consider price relative to the scope of the launch/activities you propose. The book is the first in a fantasy series, and is pretty adult and dark (lots of sex and violence), similar to, say, Game of Thrones/ Ice and Fire, so I would assume I'm targeting the same audience (late teens to late thirties?). What services would you offer and what would you charge? What additional budget would you need (ad placement or whatever else you had in mind)? Lastly, this project does not have to be a massive rush. I have up to 60 days. Thanks