The questions you are asking suggest you are less than professional and you've bought the glass only, no digitizer etc. No problem.
Know this, removing the digitizer from the glass (or vice a versa) is not recommended without considerable expertise (technique) and gear. The glass is VERY well adhered to the digitizer. Removing it without damaging the digitizer is much less than trivial. The real problem, however, is adhering the new glass back onto the old digitizer. It typically requires a vacuum sealer to get the job done right.
My advice … if you don't have the tools - don't do the job. Pay the extra $30 and get the complete screen w/digitizer replacement. Trust me, your marriage will be much happier. 😬
Bon Suerta.
Dan