It's a legit question to ask your school teachers... I encourage you to go and do that, especially if you payed for your education... Yessss, water and most of other liquids do evaporate even being a room temperature=)
You can look up the details, but in simple words, the force that "holds" the liquid together is surface tension. Liquid by itself is an ensemble of many molecules with different velocities. Occasionally, molecules gain enough velocity to overcome surface tension and to escape the surface of the water. Some molecules can come back to the water too. It is a stochastic process of going back and forth through the surface barrier.
Usually, you can observe this process in nature being near the lake on the sunny morning. The temperature starts rising when the morning comes, and the Sun starts heating up the surface of the lake. The water molecules start evaporating, creating mist. If you wait for half an hour more, you would notice, that the reverse process happens as well: condensation on the grass=)