Question A few questions regarding AR foundation [Urgent help please!]

So I am making an AR foundation app, and I have a few questions:

1. Scene Management: So I have a few scenes, and I have buttons that link the scenes with one another. Weirdly, the buttons only work when I am going from Scene 1 to Scene 2. But if I try to navigate from scene 2 to scene 1, it doesn't work Here is the code I am using:

Code (CSharp):

1.      public void LoadScene(string sceneName){
2.               SceneManager.LoadScene(sceneName);
3.        }
4.  

I attach this script to an empty game object and attach the game object in the button and declare which scene I want to switch to.

2. So say I have a 3d model that is already animated and it has a bunch of animations like walk, attack, die, jump etc. I want the model to change its animations on button click, any idea how? Basically what I have done is I spawn in a 3d model and its starting animation is idle, and say when I click on a button, i want the 3d model's animation to turn into a jump but only once.


3. Any idea of how to implement Unity's AR foundation UI toolkit in my project? I tried reading docs and it's soooo confusing omg. I am talking about this: AR Foundation Demos — Onboarding UX | Templates | Unity Asset Store

4. Can I put ads in my application and how do I do this? I am very new to all of this.

5. I want to create a cool F***ing splash screen too but IDK how to do that EITHER lord help me :/ Please help me with anything you can help me with <3

I would appreciate all the help I can get plEASE! I wanna make a really cool project