i would HIGHLY recommend at least a 2.5g critter keeper.
your fish will thank you for more space
they arent much
more expensive either tbh. and you can decorate them better.
you can leave the filter run for an hour or so, mainly to allow the water to become nice and clean/clear. make sure you rinse out the new filter. gets rid of dust or chemicals that might be on it from factory
for a 2.5g you will need to change the water twice per week 100%. filter makes no difference there unfortunetly lol.