WOW, that guy knows NOTHING about fish if he tells you not to cycle. That's terrible, i hate misguided pet store employees. You stated before that you would hate to hurt the fish and i can guarantee that if you choose to not cycle you will kill at least a couple of them. JohnnyD44 is absolutely right on the test strips. They're terribly unreliable. Moreover, they will become really expensive int he long run. Guppies can be very fragile fish. Many are inbred because breeders often try to breed them to get better colors so they sell better. Doing a fish in cycle with guppies will stress them out terribly. As Johnny said, a betta would handle the ammonia much better thana guppy.
For future reference, 95% of employees who work at petsmart and petco tell you fish care data to promote their sales. For example, by telling you that you dont need to cycle, its almost guarenteed fish will die in the ammonia spike. Thusly, you will need to restock within a couple of weeks. this means more money for the store. Although i'm sure most of the employees dont tell you the false information on purpose its what they're trained to do since most of them don't go into the job having a petcare background. Listen to the people on this forum, many have way more experience and will help you a lot more.
Lastly, excellent choice on the filter. Going for a filter designed to filter double what your tank size is, is often the right choice to ensure ur water is kept best. However, i must warn you, i used to use aquaclear, and if you do not keep up with filter maintenence, it will clog and overflow. I had major water damage in one part of my house because I left for school and my parents enver changed the filter. In 3 months the filter clogged and we switched to a canister. Also in your picture i see no filter media. To cycle right, you will need the media IN. The filter foam is a huge aprt of cycling for bacteria growth. Without it, cycling could take much much longer. I must implore that you cycle your tank before stockign it.
Bah, i keep forgetting things. As per plants, i see you got dechlorinator, but i hope you used it before adding plants. I've heard that chlorine can damage plant roots. Also, you may want to consider some for of fertilization since your water is clean right now and should be devoid of nitrates and other forms of trace mienrals needed for growth. Also your tank has no hood, at least not in the picture. Are you going for a natural light setup? If you do you must amke sure the water is balanced to avoid too much algae growth. If you do ahve a hood, its a top fin one probably from petsmart and your plants will require one with a higher spectrum to imitate sunlight because your cabomba is a medium light plant.