Dictionaries
Even if you are already familiar with Italian in a modern sense, in reading historical documents you will find a lot of archaic language and unfamiliar vocabulary. In addition to that, meanings of words can shift over time to be entirely different than their historic meanings. To this purpose, attached are a few dictionaries that you will find useful in finding historic or modern meanings of the vocabulary you encounter.
The Vocabolario degli Accademici della Crusca (written in Italian) is the first Italian dictionary, published first in 1612, and provides historic meanings of words. It can be found here: https://www.lessicografia.it/ricerca_libera.jsp
The earliest English-Italian dictionary is Florio's A Worlde of Words, published in 1598 and provides a good view of how historic Italian terms translate to 16th century English. A searchable version can be found here: https://www.pbm.com/~lindahl/florio1598/
e eFor a more modern Italian-English dictionary, you can try to use Edgren's An Italian and English dictionary, with pronunciation and brief etymologies, published in 1901 and can be found here on Internet Archive: https://archive.org/details/cu31924019173982/mode/2uphttps://archive.org/details/cu31924019173982/mode/2up