okay cool looks like youve got a kool little garden space, an ac unit, some chains and a 400watt withan HPS bulb okay so ideally for veg youd want metal halide but its not the end of the world if you want to use HPS all the way through and is actually preferred by most growers to MH all the way throughso hang your light up and pu the A/C unit away until you need it.
1.pots:4-6, 3 gallon pots or 2-4, 5 gallon pots would be ideal for a 400w
2.soil:fox farms, roots organic, youll want to stick to a light and heavily amended soil such as the first 2 i mentioned for optimal root growth and to feed seedlings early on just stay away from miracle grow or anything marketing "slow release" as the extra nutes will leave a harsh burn to your buds.
3. nutes/ water: are you going organic or not? organic youll need to do a lot of research under the organics section but for starters youll need mycchorhizal fungus, an RO filter, vermicompost and a 5 gallon tea bubbler setup oh and sugar or molasses for feeding microlife if not then you can decide what nutes youd like to buy based on your needs I always recommend maxibloom and google "kiss method" for newbs and pros alike.
that should be good to get you going, lemme know if you have any more questions