Races: You can use races from Player's Handbook.

Classes: Classes and subclasses from PHB, Xanathar's and Tasha's. (Except Artificers!)

Starting level: 1

Ability scores: Using standard array: 15, 14, 13, 12, 10, 8

HP: as in PHB + 5 hit points

Alignment: Good alignments only

Gear and gold: As per PHB for your class and background. In addition roll for a mysterious item from PHB Trinket table (page 159).