Hi Margarita!

It's important to realize that singing styles are not national in nature so much as regional, local and individual. By that I mean there is not, for example, a single American or Irish singing sytle.

In the inside front cover of The Folk Songs of North America by Alan Lomax there is a map of the Folk Song Style Areas of North America and I would suggest you take a look at this when you have the opportunity. In brief, it shows
a Northern singing style extending from about New Jersey and southern Pennsylvania, along the banks of the Ohio River, on to St. Louis and out to Laramie, Wyoming,
co-existant white and black Southern singing styles south from Maryland, West Virginia, the Ohio River and St. Louis to Dallas, San Antonio to the Rio Grande, and,
a Western singing style west from St. Louis, Ft. Smith, Dallas andan Antonio.

In Ireland, the 4 provinces are the main divider.

However, within these broad general areas, there is considerable variation locally and individually.

I would say, if you're interested in singing in an authentic style, the thing to do is to get a number of recordings of real honest-to-goodness traditional singers from the broad area you're interested in and do a lot of listening.

I hope this is helpful.

All the best,
Dan Milner