If the BB in the filter is dead (has been sitting for more than 24 hours or has been washed in chlroinated water) you will need to cycle the tank. If this is the case, clean the filter completely as any excess waste in there will only confuse the issue by introducing nitrates.
You can cycle the tank two ways - with ammonia or with fish. You can't just let the tank sit for days - months with nothing in it as it won't do anything. You need to give the bacteria food to grow and that food is ammonia or fish waste.
Get yourself a good test kit - I recommend the API Freshwater Master Test Kit. You will need to monitor your tank levels (ammonia, nitrite, nitrate) daily so you know where your cycle is at. When you have had both an ammonia and nitrite spike, then they have zeroed out and you have a high reading for nitrates, your tank is cycled.
I would recommend fishless cycling, it's less messy, more predictable, you get a larger colony of bacteria (so you can add a few fish at once) and you don't harm any fish in the meantime!
All you need to do is find yourself some pure or clear ammonia. Add a small amount and test in a couple of hours to see where your ammonia is. You need to get it up to 5ppm. Do this until you get it up to where you want it and take note of how much it took.
Then add this amount daily, test daily until you get a reading for Nitrites. Then halve the dosage it took and keep adding this daily until your Nitrites spike and then both the ammonia and Nitrites have gone back to zero.
You should then do a test for Nitrates, which if you have done the method correctly, these will be very high.
You then need to do a large water change (90-100%) to get these as close to zero as possible and then you are ready to add fish. If you can't add the fish within 24 hours, keep adding the same amount to keep the beneficial bacteria alive.
If you can get some seed material from a health and established tank (filter media, gravel etc) this will speed up the cycling process a lot.
