Welcome to the forums, first off might want to change that profile pic of yourself also be sure to post in correct sections. However here are some answers to your questions.
1. Regular seeds are seeds that are not known genders, in marajuana plants there is both female and male. Male plants produce little to no THC, the stuff that makes you high they also pollenate your other plants, make them produce seeds. Feminized seeds are just that they are generally if purchased from a reputable seed seller going to be female.
In terms of seed types there are also autoflowering and photoperiod. Photoperiod are plants that depend upon the light cycle typically for Vegetative growth it is anything longer than 18 hours with lights on and 6 hours off. For flowering/budding you will want 12 hours on and 12 hours off. For autoflowering plants the light cycle doesnt matter they can be grown in any cycle of light but typically the best cycles are 24/0, 20/4 or 18/6.
2. For a small setup you will typically want at least 1 sq foot per plant so if you are doing 6 plants you want 6 sq ft. Also plants can grow big! Be sure that you have proper space for your lights and how tall you want your plants. If you grow your plant to 1 foot in Veg it can typically double or triple in size.
Personally I enjoy growing in soil its a lot more relaxed than hydro and there is more of a learning curve. I suggest starting with soil then once you learn your way around the plants you can move to hydro.
For lighting its best to use a small light for seedlings, MH for Veg and HPS for Flowering. You will probably want a 600W Dual Ballast. Amazon has them or you can get them from your local hydro shop.
How big of a space do you have to grow in? Can also help you determine what you need, but a 600W should be good for 6 plants.
Fans depend upon what your average temperature is a 600W can be kept cool with a Inline Fan. I havent ever used any fans but that was because I had a full room couldnt make holes in walls and cheap electricity so I just kept the door to the room open and ran the AC.
3. Seeds dont give the yield, the grower does. Don't expect much from your first grow as the first time is really just a learning process. After that you can start growing bigger plants. Read as much as you can about growing as you can before growing and you can maximize your yield. I suggest going to HerbiesHeadShop.com for seeds. I have always ordered from there and had good results they also give decent freebies. Anything can be a good starter strain I started with THC Bomb as a photoperiod. Its decent and yields pretty good for all the messups I had on my first grow.
You can read the thread in my signature for more advice and also just search around the forums there is a lot of great information here. Also search google another good friend in growing
Happy grows if you need more help let me know.
