Hello! If you work with a real estate agent to help you find a rental, usually no fee's are due from you to the agent. They get paid by the home owner or landlord. Although some agents can and do charge an upfront fee, this is not normally the case. I would just ask before you use someone to show you properties.
Once you find a home you want to rent and are dealing with the landlord or home owner, you will probably need to pay an application fee prior to getting approved to sign a lease. Be sure you understand the landlord's credit and income requirements before applying to rent a home, this will save you time and money.