Splitting form into two columns?

Question

As crazy as it sounds, it's been a while since I worked with CSS and HTML. I am trying to recreate the design featured below.

However, how can I format the form that would allow me to split the current form across two columns? I am using a div to group each column with specifiying width and float in CSS, but does not seem to be working.

Any thoughts?

* {
  box-sizing: border-box;
}

body {
  background: #FFFFFF !important;
  min-height: 100vh;
  display: flex;
  font-weight: 400;
  font-family: 'Fira Sans', sans-serif;
}

h1,
h2,
h3,
h4,
h5,
h6,
label,
span {
  font-weight: 500;
  font-family: 'Fira Sans', sans-serif;
}

body,
html,
.App,
#root,
.auth-wrapper {
  width: 100%;
  height: 100%;
}

.navbar-light {
  background-color: #ffffff;
  box-shadow: 0px 14px 80px rgba(34, 35, 58, 0.2);
}

.auth-wrapper {
  display: flex;
  justify-content: center;
  flex-direction: column;
  text-align: left;
}

.auth-inner {
  width: 450px;
  margin: auto;
  background: #ffffff;
  box-shadow: 0px 14px 80px rgba(34, 35, 58, 0.2);
  padding: 40px 55px 45px 55px;
  border-radius: 15px;
  transition: all .3s;
}

.auth-wrapper .form-control:focus {
  border-color: #FBB381;
  box-shadow: none;
}

.auth-wrapper h3 {
  text-align: center;
  margin: 0;
  line-height: 1;
  padding-bottom: 20px;
}

.custom-control-label {
  font-weight: 400;
}

.forgot-password,
.forgot-password a {
  text-align: right;
  font-size: 13px;
  padding-top: 10px;
  color: #7f7d7d;
  margin: 0;
}

.forgot-password a {
  color: #FBB381;
}

.btn btn-primary btn-block {
  color: #FBB381 !important;
}

.col-left {
  width: 50%;
  float: left;
}

.col-right {
  width: 50%;
  float: right;
}

<form>
  <h3>Sign Up</h3>
  <h4>
    Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever
  </h4>
  <div class="col-right">
    <div class="form-group">
      <label>First name</label>
      <input type="text" className="form-control" placeholder="First name" />
    </div>
    <div class="form-group">
      <label>Last name</label>
      <input type="text" className="form-control" placeholder="Last name" />
    </div>
  </div>

  <div class="col-left">
    <div class="form-group">
      <label>Email address</label>
      <input type="email" className="form-control" placeholder="Enter email" />
    </div>
    <div class="form-group">
      <label>Password</label>
      <input type="password" className="form-control" placeholder="Enter password" />
    </div>

    <button type="submit" className="btn btn-primary btn-block">Sign Up</button>
  </div>
  <p class="forgot-password text-right">
    Already registered <a href="/sign-in">log in?</a>
  </p>
</form>