I don't really know what tag to use, so I'll use Design Help as I'm asking help and advice to the design of my adventure.

• My players may be around 5-7 pc's (i would place my bets more around 5-6)
• They will be starting at first level, using the milestone progression system instead of XP.
• My players are starting in a large city where use of magic is strongly prohibited do to raw magic infusing the land (whenever magic that would cast or replicate spells would occur, I'd roll on the Wild Magic table a number of times base on the level the magic replicates (Etc. if a player uses a wand of Magic Missiles and that player spends charges to replicate the spell at a fourth level, i would roll four times on the Wild Magic table).
• I'm limiting the starting availability of spell casting to only one player, and that player can not pick a spell casting class that provides divine magics like a paladin or cleric. However, if the class would gain a Spell casting ability (like the rogue gaining the spell castings ability from taking the Arcane trickster subclass) may be acceptable.
• It will most likely be a first tier low magic adventure(level 1-5, very limited magical items)
• The adventure will be about escaping the large city (however they soon discover that'll be very difficult) and surviving the infestation within the walls while discovering what to do next.

Edit to fix spelling errors and word errors, thank you Calico.