Good teachers are always needed in Peru but competition is tough. Many more people are applying than there are jobs available.
The biggest burden will be getting a workvisa. You must be able to find a school that will be able to sponsor you.
To get a good job with reasonable working conditions at one of the better schools, then a teaching qualification and good references will be a must. I often see jobvacancies for teachers in ElComercio but they require qualifications.
With just experience, it will be tough, although not impossible.
Many teachers work illegally but they usually get paid very little and often work many hours just to make ends meet.
Many people gives private lessons in their own home or at the students home. That gives you a lot of freedom and independance. (no boss is always better) Building a customer base will be slow however but after some time it can generate you a fair enough income.
Finding accomodation in Lima is easy. Buy ElComercio on Sunday and you find 100's of rental ads in all price ranges. From rooms to rent to penthouses. Food can be bought at a democratic price at markets.
You won't get rich with teaching English but with hard work and the right attitude, you can survive here. You will have to make some sacrifices. But where not? In Europe and the US, it's tough too at the moment. Many expats teach English. Many have been doing it for years.
Best advice I can give you is that you just give it a try but make sure that you arrive here with enough money and a plan B in case things don't work out that you can go back home and start up again there. Don't arrive here with no back up plan or you last nickels.