I have an abu garcia black max and recently the thumb bar has not been smooth. Its a little grindy. I was wondering how I can fix that. Thanks

Also I have reel oil and grease

did you drop it in sand? you may have got some sort of debris under the clutch or something has worked its way into the clutch mechanism inside the sideplate through the pinion. hard to say w/o seeing it. If you know how to, just take it apart and clean it. pretty simple to do, too.

did you drop it in sand? you may have got some sort of debris under the clutch or something has worked its way into the clutch mechanism inside the sideplate through the pinion. hard to say w/o seeing it. If you know how to, just take it apart and clean it. pretty simple to do, too.

Would I use oil or greese? and where would I apply it

You  would use grease for the most part but there are a couple tiny spots that I like to use a very small drop of oil on depending on how the clutch is put together. don't mix grease either, Make sure you clean all the parts in a cleaning solution before applying new lube. there's countless youtube videos on how to do this yourself. TackleJunkie81 has probably the best video series on youtube on every tiny step of breaking down/cleaning/lubing a reel.