have been using manager for whil now and i neglecting to keep record and follow inventory. Balances are totally wrong and i like to start all over again… zero out everything and start record everything correctly… what is your suggestion?

As you want to start anew just create a new business. Backup the current one just in case and store in a safe place, also take note of the Manager version number.

First step is to check if your current book inventory has any Book value.
If it is Zero, you can then check the available quantities. If it is zero.
You can start using the inventory module without any problems.
Creating inventory locations if you have more than one store, and creating your inventory items.
If your inventory has on hand quantity and they are unrealistic, you can adjust it out, either positive or negative adjustment.
After all that is done, take physical count of your inventory on hand “Actual quantity in the store” and review their historical cost and just add them via general journal. Quantity and Value.