In Florence you would find things... difficult, to say the least, but perhaps easier the younger and more talented in whatever craft you knew. At the time of the Renaissance, all meaningful means of production in Florence was tightly controlled by their respective guild, called Arti. The largest and most powerful was the cloth weaver's guild, the oldest, the dyer's guild, and included trades of nearly everything that you could think of. You were not free from the tight control of the guild, either, if your trade did not directly fall underneath one of seven to twenty-eight different guilds in Florence at the time for many trades were lumped in with their needed means of production as well. For example, painters fell under the Arte dei Medici e Speziali, the Physicans and Apothecaries' guild, because they had to go to pharmacies to purchase their dyes and pigments.

The different guilds worked as a unit to accomplish quite impressive goals. Establishing quality control, work hours, social safety nets for the families of guild members, along with instruction in their trade and craft for young boys taken in as apprentices and protection from foreign competition.

However, while that is fantastic for anyone in the guild, you are a penniless dirtmonger supposedly with no significant connections to anyone important anywhere, or you would have used them to get your children or yourself ahead in life. You can't just set up your own stall, either, since the guild might literally come and destroy your work, and have the legal impetus to do so. You can't exactly sign up for the guild, either. To join the guild you had to have three things: to have paid an entrance tax, to have some amount of competence in the craft, and to be a legitimate son of a member. Since you are penniless, it can be safely assumed that you are not in fact, a non-bastard son of member of a guild and you can't pay the entrance tax anyways.

However, you remember what I said about it being easier the young and more talented you were? The other way to join a guild was to be taken in by a Master of the Guild as a garzoni, an apprentice as a boy. Apprentices were promising young men who Masters thought might further the Guild's reputation with their skills, and were taken in to be instructed in the craft and to assist the masters in their work. Something like an internship that lasted many, many years.

The masters, or capomasetri each ran a bottege, a workshop which if you were young and talented enough, you might be taken in. It would be quite a long shot, however. With no one to vouch for you, no one to sponsor you and no one to please and favor by taking you in, a master would be taking quite the risk in taking on an utterly unknown peasant from nowhere. Your work would have to be quite exceptional, assuming upon being presented with your piece of work, they didn't just spit in your face and demand to know who's work you stole.

That said, if you could rise up through the ranks and marry the right people, you might just reach the rank of Master of the Guild, of which there were only a few in each Arti. And then, finally, you would well and surely reach the "bourgeoise" class.

This is not optional, by the way. You can't just be be only an artistic genius at this time period. My memory might be bad and I don't have m books with me, but I can't think off of the top of my head a single artist from the Renaissance that didn't find their "humble" beginnings under someone's tutelage in a workshop, in which case they already had a massive advantage over most of Florence's population. In Florence, everything was tied to the guild, unless you're taking about post-Medici ascendancy, in which case everything was tied to Cosimo's deep, deep pockets.