Urgently need newbie help

You are asking for a lot of information. First of all, yes you should coat both sides of the screen, the outside first, than the ink side. let it dry laying it flat but off of a surface in a light safe room or drying box. If you dont already have a light for exposure, you could use the God provided one, the sun. lay your screen, once it is thoroughly dried, ink side down and place and secure the positive onto the bottom of the screen. If you have a piece of glass put that over the positive to hold it in place to ensure a good clean exposure. Doing all of this in a light safe room, than i would cover the glass with a black towel or a large black shirt. Take the screen into the sun and than remove the shirt. if the sun is out, the screen should expose within 30-45 seconds. After that, time cover the screen back up with the black towel and take it back into a light safe room. Once you are there, remove the positive and using a wet sponge, wet both sides of the screen rubbing lightly on both sides thus stopping the exposure process. You can than take the screen back outside and spray it with water to clear out the image on the screen. If you are intent on using your light box, a simple halogen light, like a workshop light would do. you just have to have some way to keep the light centered over your image and screen for a few minutes as this will take a little longer to burn in the image. I would still use a piece of glass to hold down the positive to make sure light doesnt get underneath it. There are a lot of videos on Youtube, and if this makes no sense to you at all, I would suggest looking there for piece meal instructions, starting with the proper way to coat and dry a screen, than exposing your screen and cleaning the image. Good luck and Aloha