Whether designing a book or just the book cover, the choice of font is important. Think of it as a design element that will help attract the audience you want.
Of course, if you find a font you love, you may then find that graphic artists come out of the internet woodwork and say it is overused and passé. To them it probably is, but I doubt it will be to the general reader. But it might be wise to get a feel for how used it is before you decide. Some of the overused fonts might be Times New Roman, Arial, Papyrus, or Algerian, for example.
There are many fonts out there. I tried Google fonts recently and grew dizzy checking them all but I was glad I looked. Sometimes I found it hard to differentiate between one font and another - they looked so alike to my untrained eye. There are lots of other sites, too. Type Free fonts in your search box and check them all to get an overall impression of what you could use.
Some will be suited to a particular genre and
to misuse a Sci-fi font on a Romance book would be a disaster. If you are new
to this game, then the only way to get a feel for the genre type fonts is to
study the market and since we might soon be allowed out into bookshops again,
that is a delightful way of working. Until that happy day, online is the way to
go. Good hunting! You might find me there, searching for that elusive, just-right font!
PS The moody seascape has nothing to do with fonts!