Pet Advice??

Hi... im looking for advice on a few pets i wanna get... but i just wanted some info from other people.... thx! Okay so.... pet 1. syrian hamster... ik they need floorspace but all i have is a crittertrail to work with... i was going to make a cage... but cant atm... i also have the perfect cage for a dwarf but i heard they escape and bite alot... should i give one a try?......... 2. goldfish.... i have a really small tank and yes ik they need at least 5 gallon but i was gonna upgrade later on... i also considered a betta or guppies... but bettas need room too... but what if my guppie gets sucked up the filter?? ... and finally... an axolotl for my s.o he really wants one but idk where im to get all the stuff it needs..