I'm on a giant pet tanget today, so here are some friendly reminders for anyone who wants to go into fishkeeping. These tips are mostly for beginners who are just getting started in the hobby!
All fish require a clean, fully cycled tank in order to thrive. Cycling a tank can take weeks or even months as the beneficial bacteria establishes itself. A good substrate can help the bacteria thrive.
Whatever you do, DO NOT PUT ANY FISH INTO A BOWL! Putting a fish in a bowl is incredibly cruel as it distorts their vision and stresses them out, weakening their immune system and making them succeptible to bad illnesses. A bowl also cannot fit all of the things needed for a healthy fish, so it's all around bad.
It is required that you perform a 10% to 25% water change every 1-2 weeks (depending on the tank size and how dirty the tank is). Bigger tanks are typically easier to clean than smaller ones. Whatever you do, DO NOT do a full water change unless it's absolutely neccessary (ex: if your younger cousin puts a whole tube's worth of acrylic paint into the water or if your fish passes away).
Testing the water parameters is CRUCIAL if you want to make sure that your water is safe. There are Master Test Kits available, but you can also use various test strips to check for stuff such as ammonia, nitrates, nitrites, and issues with your pH. Problems with any of these can actually spell doom for your fish, so be vigilant!
Tropical fish require a heater in their tank in order to survive. They cannot survive in cold water.
Goldfish are NOT for beginners. They require a minimum tank size of 40 gallons as they grow incredibly large (6-18 inches depending on the species you get). Goldfish also produce tons of waste, which leads to a bigger risk of ammonia poisoning. Honestly, large ponds are the best option for goldfish as you can give them plenty of room to swim as well as plenty of goldfish friends!
Betta fish live in large rice paddies and ponds, not mud puddles. They require a minimum of 5 gallons in order to thrive. On top of that, their fins are long and delicate so it's crucial that you steer clear of decor with sharp edges and strong filters. Real/silk plants, smooth stones, and sponge filters are the best option. Bettas also like darker aquariums, so floater plants are highly reccommended (just don't block the light completely; your other plants need light, too!)
Speaking of bettas, it's best to keep bettas alone due to how aggressive they can be. Though they can get along with larger snails, it might not be the best idea whatsoever especially if your betta is nippy.
Arowanas are NOT a good option for beginner fishkeepers as they can grow up to 4 feet long and are known to have powerful jumping capabilities. They can break through most lids and end up on the floor. Arowanas are also incredibly pricy, with some going for over $70,000!
Well, that's all I have room for right now! Let me know if I missed anything or if I got something wrong! I'll happily add more stuff and correct any mistakes if need be! You can add on to this list with your tips and advice, too!
Remember: the most important thing to do is conduct your own research on pets! Don't just listen to the pet store clerks; they might give you incorrect information on the type of pet you want. Speak with professionals and hobbyists, read books and articles, or watch videos on how to care for a pet if you'd like! Whatever floats your boat! :D
Edit: Sorotities and bettas in community tanks are a bad idea after doing some more research.
Edit 2: A Couple of Helpful Links
How To Set Up Your First Fish Tank (BYA)
Top 10 Plants for Beginners (Aquarium Co-Op)
