what type of Automatic transmission fluid should I use in my 97 BMW 328i and where do I put in?

your car uses a special atf from shell that BMW says it doesn't has to be replaced. I think it can only be purchased at the dealer but you can get another that meets the requirements on pep boys or equal. To service the tranny is from under the car and you need the procedures to do it. it can be done by you but you need certain skills.

Its a lifetime fill. If your feeling adventures , jack the car up and remove the plug from the trans, fluid should be just below hole level. Fluid Part number #3374650012285 Motul

If you do check your fluid make sure the vehicle trans temp is at 50 degree C and the engine is running. Also with your car a global ATF will work with your transmission. But do be careful flushing your transmission on high mileage vehicles sometimes it creates more problems then it solves.