Ashley, Buy an exhaust with a vent kit. Calculate your CFM as per the square footage of the bathroom. A 90 SF bathroom will require a min of 90 CFM -100 CFM exhaust fan. (CFM means Cubic Feet per Minute).The instruction for CFM will be listed on the exhaust fan box itself. The vent kit, contains a flexible duct, an exhaust vent, duct adapter and a neoprene strip. The instruction are easy and can be a DIY. Just make sure you do not vent into the attic, This is against code.