Some of the Last Will and Testaments are on-line, on microfilm or they are at the courthouse in the county where the person died. Very old wills may be stored in archives. This varies from state to state in the U.S.
New York state has probate records, but at this point, most are not indexed.
New York Probate Records, 1629-1971 (browse images)https://familysearch.org/search/collection/show#uri=http://f...
Minnesota seems to have an index:
Minnesota Will Records, 1849-1985 (searchable index)https://familysearch.org/search/collection/show#uri=http://f...
Here is an article regarding these records in the U.S.:
United States Probate Recordshttps://familysearch.org/learn/wiki/en/United_States_Probate...
And, yes, the Last Will & Testament of a person may mention
his relatives and friends and how he would like his or her remaining assets distributed amongst them.
Feel free to ask any other questions. Good luck in your research!