Bonjour Soner, Unfortunately, there's no way to know for certain the gender of a French noun without looking in a dictionary - there isn't a simple rule that tells you, so you just need to learn the gender along with every new noun you learn.

However, we do have tips that can help with some nouns: https://www.french-test.com/revision/grammar/how-to-identify-gender-by-some-word-endings