yes feed the bottom feeding food every second day, and check a few hours later to make sure the food has been eaten and is not rotting in the gravel.
yes you should do a water change every 1 - 2 weeks. Most people try to do it every week but it depends on how the nitrates go and if you live somewhere that water is in limited supply. If you don't have water restrictions then try for once a week, or do a bigger water change (say 50%) every 2 weeks.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank