How to retrieve data from realtime database in Firebase?

I am developing an app where the user registers, enters some information and is then redirected to another page where they can see the information they entered. The information is saved in a real time database using firebase and my problem is how to retrieve that data to display? I have looked at tutorials but i do not understand how this data is able to be retrieved in an array list or something like that.

Here is my database structure, where the id is the user's uuid:

And here is how i save the data to the database:

this is the class constructor that holds the different variables being saved

  public PersonalInfo(String Id, String Name, String Birthday, String weight, String height, String gender, String Protein, String carbs, String fat, String Weightloss)
    {
        this.id = Id;
        this.Name = Name;
        this.Birthday = Birthday;
        this.weight = weight;
        this.height = height;
        this.gender = gender;
        this.Protein = Protein;
        this.carbs = carbs;
        this.fat = fat;
        this.weightloss = Weightloss;
    }

and after getting the text of the different text fields in the activity the data is saved like this:

  PersonalInfo info = new PersonalInfo(Id, Name, Birthday, Weight, Height, Gender, Protein, Carbs, Fat, Weightloss);

        databaseinfo.child(Id).setValue(info);
        Toast.makeText(this, "Data added", Toast.LENGTH_SHORT).show();

If anyone could help or give me a link to a tutorial that explains my problem, it would be much appriciated.