Air is east, south is fire, west is water and north is earth. Be careful not to confuse them. Some start in the north, I start in the east, pick anywhere you feel best, just don't get the elements mixed up or the circle might not work or be strong.
There are many ways to cast, research and find the best one for you. Go to the east, hold your index finger/wand/athame in your power hand [writing hand] out, maybe draw a pentagram, say something like 'oh watchtower of air found in the east, please be present and watch over my circle' then walk clockwise to the south, then say the same thing but replace 'east' and 'air' with 'fire' and 'south'. Continue around to each spot and back to the east. [I usually go around two more times but its optional]
For the God, Goddess and spirit, go to your alter, turn to the white candle and call to the Goddess, could be as simple as 'my Lady is welcome in my circle, please bless me with your presence.' Then light the black [or dark purple or dark blue] candle and say the same only for the God. Light the spirit candle in the center and say something similar. [Of voided some omit spirit or call on another element]
When you open the circle, go in the opposite order, thanking each element/deity for being with you in your circle and snuff out each candle. You don't have to use candles, it could be statues for the deities. The directions can be marked with candles, coloured rocks, symbols, representations of the elements, or just visualize, but most have trouble without a direction marker.