You can pass more classes into className using template literal strings. Here's an example passing in the my-2 and mr-4 you wanted to add:
import React from "react";
import logoimg from "../../assets/images/logo.svg";
import classes from "./Logo.module.scss";
const logo = (props) => {
return (
<div className={`${classes.Logo} my-2 mr-4`}>
<a href="/">
<img src={logoimg} />
<p>Resume Builder</p>
</a>
</div>
);
};
export default logo;