Welcome aboard. Since you live in LA, I don't think you will need a heater. If you use a filter, I think I would use something low powered. The tadpole should readily feed upon fish foods for now. It will eat live insects when it morphs and climbs out of the water. A healthy tadpole will have an appetite. You can do partial water changes, even if you have a filter, its still a good idea. The 10 gallon shall be fine for now, but I suspet the tadpole is a bull frog and it will need a much larger tank in time. I would not add any roommates to the frogs enclosure.