I would do fishless cycle , is simple and cheap and not inferior to other methods, You don't risk loosing fish or other animals, the best If You could ask someone who's having a fishtank and can give you some old media from established tank like an old sponge filter, piece of rock, gravel, whatever. You don't need anything fancy really. most people recommend using pure ammonia to start, but any cheap fish food flakes, would do the same thing when they go bad. You will do water changes later on anyway, so a little mess in a tank at the beginning is even better than crystal clear water. the more polutted water become the more bacteria grow, once You established a enough colony of nitrifing bacteria, You're done. it will take time and patience, the best is a couple weeks, but cycling tank is a very simple process and You don't need a lot of products, the only product i think is important is a water conditioner, like Prime etc.., because untreated water contains chlorine which will kill most bacteria.