My boss & I were in a very heated debate, I felt it was going to far & requested HR to be there if he wanted to continue the conversation & he bluntly said no... I haven't talked to my HR about it yet because the situation happened on Friday evening... I just want to know my rights & what to expect

Is your boss the top boss of the company, are you union, do you have a contract? We do not know anything about the situation from your post, more details are needed.

At my facility he is. No I'm not union nor contract. We got into a heavy debate over an inventory count being short. In the conversation I tried explaining that the inventory was right but he downgraded me by saying how he was right because his payrate is higher... conversation after that was getting out of control I told him if he wanted to continue the conversation he can get HR in here his response was no repeatedly after me asking for HR the conversation then got worse... needless to say before the day was over he did come up to me & said the inventory was right but nothing else

You need to talk to HR and find out the policies about such things. There has to be written policies about dealing with such disputes.

If your boss is top boss then HR works for him. It is not wise to argue with your boss, you need to find ways to show him what you are trying to get across without being argumentative.