Combine and use useReducer once 

import React, { useState, useEffect, useReducer } from "react";
import NAME_1 from "../UI/NAME_1/NAME_1";
import classes from "./Login.module.css";
import Button from "../UI/Button/Button";

const formReducer = (state, action) => {
  switch (action.type) {
    case "USER_EMAIL_INPUT":
      return {
        emailValue: action.payload,
        isEmailValid: action.payload.includes("@"),
      };
    case "INPUT_EMAIL_BLUR":
      return {
        emailValue: state.emailValue,
        isEmailValid: state.emailValue.includes("@"),
      };
    default:
      return { value: "", isValid: false };
  }
};

const pwdReducer = (state, action) => {
  switch (action.type) {
    case "USER_PASSWORD_INPUT":
      return {
        pwdValue: action.payload,
        isPwdValid: action.payload.length >= 6,
      };
    case "INPUT_PWD_BLUR":
      return {
        pwdValue: state.pwdValue,
        isPwdValid: state.pwdValue.length >= 6,
      };
    default:
      return { value: "", isValid: false };
  }
};

const Login = (props) => {
  const [formIsValid, setFormIsValid] = useState(false);
  const [formState, dispatchForm] = useReducer(formReducer, {
    emailValue: "",
    isEmailValid: false,
    // pwdValue: "",
    // isPwdValid: false,
  });
  const [pwdState, dispatchPwd] = useReducer(pwdReducer, {
    pwdValue: "",
    isPwdValid: false,
  });

  const emailChangeHandler = (event) => {
    dispatchForm({
      type: "USER_EMAIL_INPUT",
      payload: event.target.value,
    });

    setFormIsValid(event.target.value.includes("@") && pwdState.isPwdValid);
  };

  const passwordChangeHandler = (event) => {
    dispatchPwd({
      type: "USER_PASSWORD_INPUT",
      payload: event.target.value,
    });

    setFormIsValid(
      formState.isEmailValid && event.target.value.trim().length > 6
    );
  };

  const validateEmailHandler = () => {
    dispatchForm({ type: "INPUT_EMAIL_BLUR" });
  };

  const validatePasswordHandler = () => {
    dispatchPwd({ type: "INPUT_PWD_BLUR" });
  };

  const submitHandler = (event) => {
    event.preventDefault();
    props.onLogin(formState.emailValue, pwdState.pwdValue);
  };

  return (
    <NAME_1 className={classes.login}>
      <form onSubmit={submitHandler}>
        <div
          className={`${classes.control} ${
            formState.isEmailValid === false ? classes.invalid : ""
          }`}
        >
          <label htmlFor="email">E-Mail</label>
          <input
            type="email"
            id="email"
            value={formState.emailValue}
   The letter p should appear at least 41 times.
user