switching between pages with tkinter in python

Make a new Frame. Place the buttons. And modify functions. Try this code -

from tkinter import *
from tkinter import ttk

class Cinema():
    def __init__(self, root):
        self.root = root
        title = Label(self.root, text="Bravo Cinema", font=("Helvetica", 40, "bold"), foreground="orange", background="#46464a").pack()
        
        #main navigation buttons
        self.movies = Button(self.root, text="View Movies", font=("Helvetica", 15), fg="orange", bg="#46464a", activeforeground="orange", activebackground="#2c2c2e", cursor="hand2",
                             command = self.view_movies_UI)
        self.movies.place(x=30, y=110)

        self.add_movie = Button(self.root, text="Add Movie", font=("Helvetica", 15), fg="orange", bg="#46464a", activeforeground="orange", activebackground="#2c2c2e", cursor="hand2",
                                command = self.add_movie_UI)
        self.add_movie.place(x=185, y=110)

        self.bookings = Button(self.root, text="View Bookings", font=("Helvetica", 15), fg="orange", bg="#46464a", activeforeground="orange", activebackground="#2c2c2e", cursor="hand2",
                               command = self.view_bookings_UI)
        self.bookings.place(x=320, y=110)

        self.frame1 = Frame(self.root,background="#46464a")
        self.frame1.place(x=0,y=160)
        
    #view movies
    def view_movies_UI(self):
        #label

        try:

            for widget in self.frame1.winfo_children():
                widget.destroy()

        except:
            pass
        
        lbl_all_movies = Label(self.frame1, text="All movies", font=("Helvetica", 13), bg="#46464a", fg="orange")
        lbl_all_movies.pack()
        movies_frame = Frame(self.frame1, bg="white")
        movies_frame.pack()

        #tree view table
        movie_tree = ttk.Treeview(movies_frame, column=("#1", "#2"), show='headings')

        #columns and headings
        movie_tree.column("#1", anchor=CENTER, width=60)
        movie_tree.column("#2", anchor=CENTER, width=110)
        movie_tree.heading("#1", text="ID")
        movie_tree.heading("#2", text="Name")
        movie_tree.pack()

    #add movie
    def add_movie_UI(self):

        try:

            for widget in self.frame1.winfo_children():
                widget.destroy()

        except:
            pass

        
        #entry boxes
        lbl_movie_name = Label(self.frame1, text="Movie Name:", font=("Ariel", 11), bg="#46464a", fg="white")
        lbl_movie_name.pack()
        txt_movie_name = Entry(self.frame1, font=("Ariel", 10), width=40, bg="#46464a", fg="white")
        txt_movie_name.pack()

        lbl_run_time = Label(self.frame1, text="Movie Length (minutes):", font=("Ariel", 11), bg="#46464a", fg="white")
        lbl_run_time.pack()
        txt_run_time = Entry(self.frame1, font=("Ariel", 10), width=40, bg="#46464a", fg="white")
        txt_run_time.pack()

        lbl_genre = Label(self.frame1, text="Movie Genre/Genres:", font=("Ariel", 11), bg="#46464a", fg="white")
        lbl_genre.pack()
        txt_genre = Entry(self.frame1, font=("Ariel", 10), width=40, bg="#46464a", fg="white")
        txt_genre.pack()

    #view bookings
    def view_bookings_UI(self):

        try:

            for widget in self.frame1.winfo_children():
                widget.destroy()

        except:
            pass
        
        #label
        lbl_all_bookings = Label(self.frame1, text="All Bookings", font=("Helvetica", 13), bg="#46464a", fg="orange")
        lbl_all_bookings.pack()
        bookings_frame = Frame(self.frame1, bg="white")
        bookings_frame.pack()

        #tree view table
        booking_tree = ttk.Treeview(bookings_frame, column=("#1"), show='headings')

        #columns and headings
        booking_tree.column("#1", anchor=CENTER, width=60)
        booking_tree.heading("#1", text="ID")
        booking_tree.pack()


if __name__ == "__main__":
    root = Tk()
    root.geometry("700x700")
    root.title("Bravo Cinema")
    root.configure(background="#46464a")
    bravo = Cinema(root)
    root.mainloop()

I used -

try:
    
     for widget in self.frame1.winfo_children():
            widget.destroy()

except:
      pass

to delete the frame's content.

If you run this you will see that the old UI gets deleted.

(I have used .pack(), so the buttons may not be positioned the way you wanted them. So, change it such that it matches for you)

Edit:

If you want to use `.place()`, then you should give the frame a definite size like - `Frame(self.root,width=SOME_VALUE,height=SOME_VALUE)`

If you give a size then you can use `.place()` as needed (Give it some size such that it looks good. So, first change the frame's color to white, so that you can see for yourself the size of the frame and then modify the width and height)