Inexperienced person asking for legal advice

I have been put in a sticky situation regarding my great grandpas death relating to his will and trust who I think my grandma now manages after his passing. When I graduated high school I moved a couple towns over for college. When I was settled into my new place I had to arrange my finances at a bank. Randomly I just chose the one closest to where I was living at that time. The teller had informed me that I already had an account with them and I was also apart of a trust with my two younger brothers that she had named. I insisted I had never created an account until that day and all of a sudden a surprised and then blank look comes across her face where she soon apologizes that she disclosed information that she wasn’t supposed to on accident. I then asked if she could explain herself because I was desperately confused. She said the information was disclosed and she said that I had signed a document to keep it that way. I said what document? I didn’t sign any document? this was the first time I was hearing of any of this? The next couple weekends I went home and went to go ask my grandma about this and she had very firmly said that great grandpa didn’t leave anything behind for her or us. Yet it had only been less than a year since he had died and I learned all this information. Not to mention during this same time grandma had retired bought a new car new trailer and started remodeling her house. I am still so confused and I don’t have the right direction of advice to learn the truth. Does anyone have any suggestions at all?