DS wants fish for his birthday - help!

[ItsalwaysLTB]

I have no idea. We have an old fish tank that belonged to DH and BIL so we are going to reuse that but beyond buying a filter I am clueless! I'd really like to keep the fish alive, we're going with cold water fish first but I'd love some tips on what fish live longest and how to help them live well.
Thanks!

Go and have a look at your local fish shop (not pets at home) and have a chat with them, ime fish people are always keen to share knowledge!

I've recently done loads of research in to this as my son wanted fish for Christmas. Firstly, you need to find out the volume of water your tank will hold as it makes a big difference as to which type of fish you can keep and how much maintenance it will require (smaller tanks need more than larger ones).
I watched loads of you tube videos and read lots of fish keeping sites and learnt loads. My son is only 5 so I knew it would be up to me to do all the care!

Unless it’s a massive tank, I wouldn’t go for goldfish. I’d be tempted to put a heater in and go for a tropical community - for a first tank (depending on size) you could have a good selection of fish and shrimps. If it’s a small tank, maybe a single male betta? They come in some lovely colours 👍

Danios. They are fine in room temperature water and dead easy to keep in groups.