Most European languages are all related, going back to a hypothetical (but generally accepted) proto-language we call Proto-Indo-European. A lot of features of modern European languages- including genders and cases- go back to PIE. English is part of the conglomeration of PIE-descendants, on the Germanic branch (meaning that English and modern German are pretty closely related). English had gendered nouns until fairly recently. Gender started falling away as a morphological category in the 10th century, starting in the north of England, and the trend swept south, with the grammatical gender being pretty much gone by the mid-14th century. This was broadly concurrent with the disintegration of English's inflection system (we used to stick endings on nouns that determined whether the noun was the subject, object, indirect object, etc.). Broadly, Old English had gender and inflections, Modern English has neither (mostly), and Middle English was in transition between the two.

Modern English retains vestiges of gender in our pronouns- he, she, it. Likewise, the only remains of the inflectional system is in our pronouns- I/me, he/him, who/whom/whose.

As to why English lost its genders and inflections, we're not really certain. You might try posting on r/linguistics, as this question definitely falls more in that area of expertise than in history.