\
No matter whether or not you do a fishless cycle or keep the fish (not the best way to go) you need to get an API Freshwater Master test kit. Without it, there is no way to know when to do a PWC (partial water change) or how much of a PWC to do.
You can't tell by looking if the water needs to be changed or not. It's about chemicals you can't see. Just like the pollutants in the air, It's the stuff we can't see that's toxic. The stuff we can see is just dirt.
Also, you don't need to clean the tank, you need to clean the water.
You actually want some bacteria (NitrAtes) to grow inside your filter and your gravel and on the plants.
And the only way to know when that has happened is with the Master test kit. Don't let the FS (fish store) sales people talk you into test stripes. They are not accurate and in the long run end up costing you more.
Also for
If you decide on keeping the fish while doing your cycle, you'll need to be much more diligent about testing and PWC. For that you will still need the Prime but, you would also need to use a Stress Coat or Stress Guard with every PWC. When doing a cycle with fish, you need to keep the ammonia and or nitrItes below .25ppm, or your fish can and will get sick and die.
Once you decide which way your going to go, let us here on AA know and there are many who can help you through it all.