All-around newbie household

[RxGambler]

I haven't had any fish since my parents had a 20 gallon or so tank when I was a wee little guy 30+ years ago, so experience is basically zero.

Our kids are becoming of age (3.5 & 6) that they would like a pet to help with, so of course fish are a likely candidate. Kids are kids, therefore not looking to dump heaps of cash into this if/when their interest wanes, so looking to stay small with easy, hardy fish at first.

Maybe a 2.5-5 gallon tank for a betta or a 5 gallon tank for something else that's well-suited for beginners?

 

[tamtam]

Well contrary to what most people think smaller tanks are actually harder to maintain than bigger tanks. A bigger tank is far more forgiving than a small tank for toxin spikes.

I would suggest nothing smaller than a 5 gallon for a betta. It will need a heater and a filter.

A 5 gallon really does not leave you many options, it's actually really small and most of the fish you will find in a fish store are going to need much larger. Even a 10 gallon has limited options.

in a 5 gallon other than the betta option you could do a shrimp tank

maybe some nano fish. I don't know much about these fish but I think maybe a few chilli rasbora, ember tetras or celestial pearl danios might work. IME these aren't the easiest fish to come across however.

Fish keeping really isn't what people expect it to be. It's not nearly as easy as adding fish to water. I often think it's more expensive than people expect. The price difference between small tanks and big tanks really isn't a whole lot either.

You are going to need to learn about how to cycle a tank as well. This is a great article on how to start a tank and will point you in the right direction.

Guide to Starting a Freshwater Aquarium - Aquarium Advice

 

[RxGambler]

tamtam-- Thanks for the advice and link! We're just starting to research obviously and this seems like a great spot to begin.

After looking over the physical dimensions, a 10 gallon tank is suitable for the spot we've got picked out and really isn't much larger footprint-wise than a 5... so that's definitely a possibility.