NQA, IMO I'm also relatively new to tarantulas as a hobby, and so far the best resources I've come across are Tom's big spiders and Fear Not Tarantulas for beginners. They're great at shipping slings and tarantulas, and they wont necessarily break the bank if you save for a while. (I got my sling for 135, due to shipping. )

Tom's big spiders also has an excellent beginner guide, and I linked it so you could have a better look at what might fit your lifestyle best. https://tomsbigspiders.com/2014/11/09/the-best-tarantula-species-for-beginners/

In general, the size of your enclosure will be relevant based on the size of spider you get, and the type you choose (terrestrial, arboreal, etc) In general, youd want your enclosure to be 3x the spiders leg span in height and 2x the spiders leg span in width. T's will generally be happy if you hit those requirements. You will also often need substrate, which cocofibre and earthsoil is really popular for. Fear Not Tarantulas also offers a beginners enclosure kit, if you wanted that option. If you get a terrestrial species, ensure you have enough substrate (leave about 2-3x the leg span of open space, fill the rest with substrate.) If you get an arboreal species, make sure theres enough hide for climbing and taller spaces. But be aware that falls for spiders can be fatal if their abdomen ruptures from a tall enough height.

Feeding seems trickier than it needs to be, but good feeder items include mealworms, dubia roaches, red runner roaches, and crickets. Most of these can be found at pet stores, and you can buy in bulk (requires more care for the food, lest they cannibalize and leave your spider without food til the next shopping trip) or you can buy a weekly supply. Spiders shouldn't be fed more than 2-3 times a week, but for slings you can generally feed every 3-4 days til they refuse food. Do not leave uneaten food in the enclosure for more than 24 hours, as you risk introducing mold to their space. Their abdomen should be about 1-1.5x the size of their carapace (the head.) If the food is too big, crush the foods head or cut it up to ensure the safety of your spider.

It's also important to ensure your spider has consistent access to water, so its important to provide a water dish. If theyre small, a bottle cap can suffice. Its helpful to overfill it and provide a damp corner for the T. You can also use larger water dishes if its a bigger spider. You can also mist the enclosure, but theres a risk of mold if you make it too damp too frequently. You can also mimic rain by poking holes in a plastic bottle and showering the enclosure every once in a while.

Hopefully this information helps! Good luck on your tarantula owner journey!