What size is your tank and what fish do you have in there (and how many)?
The only thing you should add to the tank is dechlorinator to the tap water before you put it in. Any bacteria in a bottle products are generally not of much help.
What test kit are you using? If it's strips, I highly recommend getting the API Master Liquid Test kit.
Test your water daily; any time ammonia and/or nitrite are over .25, do a water change to get them to as close to 0 as you can. Same with nitrates over 20. This may mean a very large water change, it may mean more than one in a day; let the test kit dictate when and how much of a water change to do. If you can get Prime, which is an excellent dechlorinator, it will also help detoxify some of the toxins between water changes (but not to be used in place of water changes). You'll be doing this for some weeks while the tank cycles; ammonia will slowly rise and our water changes will increase. Then ammonia will start to come down and nitrites will rise and increase. Eventually when both ammonia and nitrite fall to 0 on their own and stay there (without water changes to get them down) your tank will be cycled. Don't add any new fish for a while and just be prepared to test the water daily and do water changes as needed for the next 3-6 weeks (on average).
There are two links in my signature: new tank with fish and what is cycling. Read them both and they'll help.
Don't worry about your PH. Test it daily too but as long as it stays stable it's fine for the fish. If it starts fluctuating then that could be an issue and one we can address if it happens.
If you can get some media (a filter pad, gravel, a decoration, etc) from a healthy established tank that is the best thing to use to help seed your filter and move the process along. Otherwise just be patient and it'll happen on its own.
Good luck.