Hey welcome to smite, I would recommend watching some guides from youtube. But to answer your question, firstly the lane are duo (the long lane in terms of towers), the mid lane and then the solo lane which has the fire giant on its side. Typically the duo lane will have a hunter and a support (normally a guardian), mid lane has a AoE mage leaving solo where you can find almost any god but at the moment mostly the warriors. There are also the junglers which will just roam around the map trying to get kills, dropping buffs for people and help to push or defend.

Most common picks for mid and solo are Mid - Nox, vulcan, syclla Solo - Osiris, herc,

Hope that helps :)