public class DBConnection {
    private final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    private String host;
    private String root;
    private String password;
    private String nameDb;
    private String url;
    private Properties properties = new Properties();
    private Connection connection;
    private PreparedStatement preparedStatement = null;

    public DBConnection(String host,String root,String password,String nameDb){
        this.host = host;
        this.root = root;
        this.password = password;
        this.nameDb = nameDb;

    }

    public DBConnection(String url,Properties properties){
        this.url = url;
        this.properties = properties;
    }

    public void iniProperties(){
        url = "jdbc:mysql://"+host+"/"+nameDb;

    }

    public void init(){
        if(connection == null) {
            try {
                Class.forName(JDBC_DRIVER);
                connection = DriverManager.getConnection(url + "?useSSL=false", root, password); // вот здесь ошибка
            } catch (SQLException e) {
                e.printStackTrace();
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            }
        }
    }

public class Home_form extends javax.swing.JFrame {
     DBConnection connection = new DBConnection("192.168.194.115", "admin", "0000", "test_lessons");
     private String name_ = "";
     private String lastname_ = "";
     private String fathername_ = "";
     private String password_ = "";
     private String login_ = "";
     private java.util.List<String> List = new ArrayList<>();



     /**
      * Creates new form Home_form
      */
     public Home_form() {
         initComponents();
         acept.setVisible(false);
         name.setVisible(false);
         lastname.setVisible(false);
         fathername.setVisible(false);
         about.setVisible(false);
         jLabel3.setVisible(false);
         jLabel4.setVisible(false);
         jLabel5.setVisible(false);
         jLabel6.setVisible(false);
         connection.iniProperties();
         connection.init(); //ошибка

at com.testing.DBConnection.init(DBConnection.java:41)
    at com.testing.Home_form.<init>(Home_form.java:48)
    at com.testing.Home_form$7.run(Home_form.java:338)