

First time DM, Crimson Throne AP
As it says first time DM, so far i have 3 players with possible 2 more coming. besides that, any advice for the campaign? im planning on doing Milestone, also full lvl HP and spell healing does max. I'm also doing brutal crits (full damage) and lingering injuries.
I started a prologue mission, had the PCs accidentally meet together, follow one of Gaedren's street guys, random NPC, try to take him down, instead he got killed before they got the info, got jumped by Giggles and his thugs. Gave them some extra GP for other items, not much over 100gp to split. Had Giggles escape so they will meet him again. Made up a ledger so they follow something later. once they got to Zellara's after the harrow reading they went to Gaedren's hideout. I ended the session there.
basically I'm asking for First time DM advice and advice on the Curse of the Crimson Throne AP. How should prepare? We play at a game store for 4-5 hours, I have played with all three before. They like to investigate things and get side tracked sometimes.