How to provide validation for the users model in views itself in django(not the custom user model)?

Question

I am having user model in the models.py and the every user even the repeated user emails and usernames are being stored in the database but I need the validation of email and password upto 8 characters in the views.py My models.py is

class users(models.Model):
    email=models.CharField(max_length=50,default='0000000')
    password=models.CharField(max_length=50,default='0000000')
    room = models.ForeignKey(rooms,on_delete=models.CASCADE)
    goal = models.ManyToManyField(goals)
    style = models.ManyToManyField(designs)

My views.py

def user_register(request):
    if request.method == 'POST':
        email = request.POST['email']
        password = request.POST['password']
        room = request.POST['room']
        g=goal=request.POST['goal']
        g = g.split(',')
        s=style=request.POST['style']
        s=s.split(',')
        user = users(password=password,email=email)
        user.room=rooms.objects.get(pk=room)
        goal = goals.objects.filter(pk__in=g)
        style = designs.objects.filter(pk__in=s)
        user.save()
        user.goal.add(*goal)
        user.style.add(*style)
        return render(request,'home.html')

My template is:

<div class="card-body">
              <form action="{% url 'car:user_register' %}" method="POST"  >
              {% csrf_token %}

              <div class="form-group">
                <label for="username">Username</label>
                <input type="text" name="username" class="form-control" required>
              </div>
              <div class="form-group">
                <input type="hidden" name="room" id="name" value=" ">
              </div>
              <div class="form-group" >
                <input type="hidden" name="goal" id="goal" value=" ">
              </div>
              <div class="form-group" >
                <input type="hidden" name="style" id="style" value=" ">
              </div>


              <div class="form-group">
                <label for="email">Email</label>
                <input type="text" name="email" class="form-control" required>
              </div>
              <div class="form-group">
                <label for="password2">Password</label>
                <input type="password" name="password" class="form-control" required>
              </div>

              <input type="submit" value="Register" class="btn btn-secondary btn-block">
            </form>

          </div>
        </div>
      </div>