All nouns are either masculine or feminine:
Masculine nouns will have le or un as an article. They will also finish in -age, -ment, -eau, -phone, -scope, -isme
Exemple: Le fromage, un téléphone, le séisme
Feminine nouns will have la or une as an article. The end of words will also be different with -tion, -sion, -té, -ette, -ance, -ence, -ure, -ode/ade/ude
Exemple: une solution, la salade, une société
There wil be exceptions with -é, -er, -ée, -ère