You're going to get a lot of "one hit wonder" yahoo's that'll tell you what to do, but not how to do it.
Take a look at what you'd like to accomplish with this first grow. Are you trying to get a harvest? Are you just looking to see how the plant grows? Would you like to experiment with a training method like LST, Scrog, Topping/Fimming, or Super Cropping (you'll want to search this stuff up). Once you clearly identify your goals and expectations I think we could fine tune an answer for you.
The basics for you include research and knowledge. This is a full blown hobby and there is a lot to know and a lot to sift through for you to reach success. For the beginner though there are just a few areas you need to focus your energy and attention to. Light, Ventilation, and Solution.
Lighting on the inexpensive end can be done with CFL bulbs. Clamp light reflectors or plug sockets will work well with these homemade lighting systems and it can all be found at the hardware store. Day light spectrum CFL bulbs provide more blue light and is a better choice of lighting because all the light is in a spectrum the plant can utilize. Soft white and cool white bulbs offer far less energy to the plant then the day light bulbs will. Figure you need 100w to 150w of CFL bulbs at the finish for one plant. Two plants can be grown with just a little more light and some creativity in the placement of the bulbs between plants. I prefer 20w to 30w (Actual wattage, never equivalent) CFL bulbs because they can be, and must be, kept within 2 inches of the plant. I keep mine as close as 2cm away. Expect to spend anywhere from $35 to $60 on your lighting between the timer, the bulbs, the sockets, and the power strip.
Ventilation is as important as your lighting. You don't need some killer fan for these bulbs, but you do need to be moving air around at a constant rate. Depending on your setup a standard desk fan might work fine. You may need to get an axial fan (maybe 4") if your setup is in a custom cabinet to exhaust the heat. Expect anywhere from $20 to $40 for your ventilation needs.
Solution is the mixture of nutrients and water, mostly water though. The important thing for a new grower is to focus on the pH of their grow, and owning a pH wand is about the only way to do this accurately. Of the equipment you buy this wand might be the most important piece to keeping your grow healthy. A one part nutrient system (Advanced Nutrients ME Tea Grow and Bloom or BioCanna BioVega and BioFlores) designed for Vegetative life and for Flowering life is pretty important. I suggest you grow in a good organic soil like Canna BioTerra or Roots Organic Soil mix, but if you can't get these there's always your local nursery organic soil. Try to steer clear of Miracle grow, but if you have to get them I suggest the Rose Potting Soil or the Orchid Mix. Marijuana is a flower, not a vegetable, and these soil mixes are made for pissy little delicate bitch ass flowers like roses and orchids. Keep your pH around 6.4 to 6.6, with 6.5 being ideal. The cost of nutrients is going to hit you a little hard because you're going to purchase it by the liter, which is going to be enough nutrients for dozens of plants. Expect maybe $40 on nutrients, and another $40 to $50 on pH equipment to get it right the first time and not waste time and money on pool pH equipment.
There's more to it than this. MUCH more, light tightness, humidity and temperature control, watering schedules, soil amendments, etc etc. You must take it upon yourself to learn what you can then to try it out. Take what works and move forward from there improving with every new grow. You don't need to buy genetics, especially if you're on a fixed budget. Shipping alone is going to be $25. So get yourself a couple bag seeds, I say start 4 or 5 of them and keep two. Take them to maturity, hope for girls, and take what you can get. But, if you keep your lighting adequate, your ventilation sufficient, and your solution in range then you're covering the things that MUST be covered.