I can't help you with finding a place to live, but as for work, you are going to have to look for jobs that pay under the table and since you mention Rome, this is a good place since they should offer a lot of these jobs. One of these positions is bar work, so it should help you that you do have bartending skills. Also, the tourism industry is another area that you can look for work in as their are many native english speakers giving tours.
Once you arrive, I believe that you are supposed to apply for a residence permit with the local police (you don't have to do this, but get caught and they will deport you). For this you just need to show that you have a certain amount of money (not sure of the amount, but it is nothing too bad) and pay a fee. Since you are not from the EU, the only way you can get a legal job is if an employer can prove that you have a skill that no one else in the EU has, which is pretty much impossible to do.
Rent in Rome is probably expensive as it is in most of the major cities, but the other costs of living should be relatively cheaper compared to the other major cities of Europe. Good luck!