If the filter is dry the bacteria will be dead, even if it is wet they need an ammonia source to keep them alive, so you will probably need to start from scratch. I would scrape all the algae etc off the tank, fill it up with whatever substrate you are using and dechlorinated water, then put your filter on and make sure it is all working before you get your axie. Test you water for pH, nitrite, ammonia and nitrate so you have a base to start from. Then test water and change 20% every day if needed. I don't know if it will be easier with a smaller one, as they are quite messy, but someone more experienced will probably be able to help you with that. Be prepared for the tank to take several months to cycle. If you can get a few live plants that might help.