Unfortunately both my parents died more than 3 years ago. I took a lot of their dishes,etc. Those that I know are milchik or fleishik I have been using. However there are a number of pots and pans in practically new condition that I don’t know whether they are milchik or fleishik. They have been sitting in my cupboard all this time and I would like to use them.Can I?

Yes you can, as long as they can be koshered. Metal pots can be koshered. They should be roughly cleaned and all removable parts should be removed. Then boil a bigger clean pot (Milchig or fleishig) that wasn’t used for 24 hours and dip the entire pot in for a few seconds, make sure the water gets to all over the pot (even if not in one go) and that the water is bubbling while the pot is in it. Take it out and rinse with cold water. Metal frying pans that are plated with non-stick Teflon-like material can't be koshered. Metal frying pans that are used with a thick layer of oil should be koshered like the pots. Baking pans have to be blowtorched to red hot temperature, that is not a simple practice and I recommend using new ones.