2. There are plenty of guides and books on the internet. Look for what's recommended now on Reddit.

3. That really depends on how much you want to grow, and your budget. You need an enclosed space if you're not going to grow autos, lights, fans, substrate and fertiliser.

I'm assuming you're on a budget, so:

The enclosed space can be anything from a 300$+ tent to two stacked buckets or a wheelie trashcan. Hell, even a big cardboard box should do for a grow or 2. The only requirement is that you can limit light, and can ventilate.

For the lights, if you're on a budget use led lightbulbs and remove the diffuser. Phillips had the best lm:w ratio when I was doing it. Check on Reddit for specific guides, but if I remember correctly you need 20-30w/ft2, 4000k for both veg and flowering. When you get skilled, you'll get slightly over 1g/w. Get a mechanical timer as well for the day-night cycle.

Fans: used pc fans are a good temporary measure, but a toilet extractor fan is much better for not a lot of money.

Substrate and fert: I suggest coco coir. It requires watering till runoff 1-2 times a day, and you have to learn how to make nutrient solutions, but IMO it's far easier and cheaper than soil or pure hydro. Later on you can automate it with a couple of tanks and a water pump.

Go to a farm store and get 3 staged fertiliser bags (usually like 1 bag for seedlings, 1 for veg, 1 for flowering and fruiting), and a bag of calcium. Tomatoes and weed have extremely similar requirements so ask the staff for help, and to suggest to you a brand that's used for drip systems (it means they're completely water soluble).

For the best results, look for a fert with no C. That way you can make a big batch of concentrated solution and it won't grow bacteria.

WARNING: special weed fertilisers in bottles are a complete scam, avoid them. Dry fertiliser for farmers is the way to go.

You'll also need litmus strips and some acid. I got these at a hydro store.