If I leave in Fl and I can't pay my rent? How long do I have to leave the house if the landlord ask me to and how is the process

The landlord will post a 3 day "pay or quit" letter. If you fail to leave or pay after 3 days... the landlord will proceed with eviction... which in Florida can take anywhere between 1 to 3 weeks... depending on how busy the courts are. Having an eviction on your record will effect your credit report/rental history and make it very difficult to rent elsewhere. If the landlord receives a judgment against you for unpaid rent... he can garnish your salary, attach your bank accounts and seize your IRS returns. A judgment will follow you around for up to 10 years.

Leaving voluntarily or via eviction does not free you from the rent. You still owe for the months that you have been living there. The landlord may have to sue you if you can't/won't pay willingly. If you walk away from a lease you owe until the LL can find a new replacement tenant plus advertising expenses.