Interest Check: slightly homebrewed DnD
The homebrew touch would be that your character's past includes a development period, where your char had negative XP and was just learning about life and about the various classes. Some minor adventuring was involved while assisting an instructor or leader. Your char started with 1 HD and might have gained 1 more HD before reaching XP 0 and being in a position to choose a class and add that class's starting HD to their HD total. Your char also acquired some knowledge of the world and life and some extra profs and skills, and maybe some extra equipment and gold.
Effectively, your char starts with extra HD from their training adventures, their own place in the world based on their development experience and learning, and maybe extra gear and gold. Adventures would be adjusted to fit the boosted Level 1 character.
This can be either 3.5e or 5e depending on what people want. I'm even willing to consider 4e or 2e. Let me know by posting in this thread so we can talk about it.