Collision with wall and each other? Pygame

Question

I am making a game where cars can move however they cannot go through each other or go out of the map. I am not sure how to make it so that firstly the objects will stop at the edge of the map, and secondly that they cannot go through each other (make the user not be able to move them towards each other when they're touching). Any help would be appreciated. Thank you.

Here's my code:

import pygame, random, time

pygame.init()

class Point(pygame.sprite.Sprite):
    def __init__(self,x,y):
        super().__init__()
        self.rect=pygame.Rect(x, y, 1, 1)


class Car(pygame.sprite.Sprite):
    def __init__(self,hv,image,spawnx,spawny):
        super().__init__()

          
        self.image= pygame.Surface((100,100))
        self.image = image
        

        self.type = hv

        self.rect = self.image.get_rect()
        self.rect.x = spawnx
        self.rect.y = spawny

      
    

        cars.add(self)

    def move(self, dx, dy):
        self.rect.x += dx
        self.rect.y += dy

h="horizontal"
v="vertical"
horizontal=[]
vertical=[]

screen = pygame.display.set_mode((1150, 650))


background_image = pygame.image.load("carpark2.jpg")

cars=pygame.sprite.Group()


clock = pygame.time.Clock()

done = False

red=Car(h,pygame.image.load("redcar.png").convert_alpha(),100,100)

blue=Car(v,pygame.image.load("bluecar.png").convert_alpha(),700,100)
yellow=Car(h,pygame.image.load("yellowcar.png").convert_alpha(),100,200)
purple=Car(v,pygame.image.load("purplecar.png").convert_alpha(),500,100)
orange=Car(h,pygame.image.load("orangecar.png").convert_alpha(),100,300)
white=Car(v,pygame.image.load("whitecar.png").convert_alpha(),900,100)
green=Car(h,pygame.image.load("greencar.png").convert_alpha(),100,400)
brown=Car(v,pygame.image.load("browncar.png").convert_alpha(),600,400)
pink=Car(h,pygame.image.load("pinkcar.png").convert_alpha(),100,500)
black=Car(v,pygame.image.load("blackcar.png").convert_alpha(),800,400)

for car in cars:
    if car.type==h:
        horizontal.append(car)

for car in cars:
    if car.type==v:
        vertical.append(car)

current_car=red       

while done==False:
    clock.tick(30)
       
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True

        if event.type == pygame.MOUSEBUTTONDOWN:
            x,y = event.pos
        
            
            for car in cars:
                if car.rect.collidepoint(x, y):
                    current_car = car

        
      
        if event.type == pygame.KEYDOWN:
           
            if event.key == pygame.K_LEFT:
                if current_car in horizontal:      
                    current_car.move(-50,0)
            if event.key == pygame.K_RIGHT:
                if current_car in horizontal:
                    current_car.move(50,0)
            if event.key == pygame.K_UP:
                if current_car in vertical:
                    current_car.move(0,-50)
            if event.key == pygame.K_DOWN:
                if current_car in vertical:
                    current_car.move(0,50)

    screen.blit(background_image, [0, 0])
    cars.draw(screen)
    pygame.display.flip()

pygame.quit()