postgresql – Simple website sql database

I’m getting into backend with postgresql and I would like to know how much of my example would fit for a real website database, just for storing and then displaying it on website.

create table clients (
    id BIGSERIAL PRIMARY KEY,
    first_name VARCHAR(50) NOT NULL,
    last_name VARCHAR(50) NOT NULL,
    age INT CHECK (age >= 18) NOT NULL,
    email VARCHAR(70) UNIQUE NOT NULL,
    password VARCHAR(100) NOT NULL,
    card VARCHAR(70) DEFAULT ('undefined') UNIQUE NOT NULL,
    joined TIMESTAMP NOT NULL,
    country VARCHAR(50) DEFAULT ('undefined') NOT NULL,
    language VARCHAR(50) DEFAULT ('undefined') NOT NULL
);

insert into clients (first_name, last_name, age, email, password, joined, language) values ('Rustie', 'Matchell', 18, 'rmatchell0@mayoclinic.com', 'OSauq0z2suY', '2021-04-18 05:26:40', 'Kurdish');
insert into clients (first_name, last_name, age, email, password, card, joined, country, language) values ('Ulric', 'Hoggins', 20, 'uhoggins1@goo.gl', 'M4hnFLJ5XeP', '30243414381012', '2021-02-20 08:07:13', 'China', 'Mongolian');
insert into clients (first_name, last_name, age, email, password, card, joined, country, language) values ('Sephira', 'Bayly', 26, 'sbayly2@rambler.ru', 'INL57w6gXe', '5100138794351466', '2021-04-25 06:17:26', 'North Korea', 'Gujarati');
insert into clients (first_name, last_name, age, email, password, card, joined, country, language) values ('Hermine', 'Fassman', 29, 'hfassman3@smh.com.au', '1UX4TApQMEuV', '3552094428434244', '2021-06-18 06:48:54', 'Indonesia', 'Albanian');

RESULT:

 id | first_name | last_name | age |            email             |   password   |        card        |       joined        |        country        |  language
----+------------+-----------+-----+------------------------------+--------------+--------------------+---------------------+-----------------------+------------
  1 | Rustie     | Matchell  |  18 | rmatchell0@mayoclinic.com    | OSauq0z2suY  | undefined          | 2021-04-18 05:26:40 | undefined             | Kurdish
  2 | Ulric      | Hoggins   |  20 | uhoggins1@goo.gl             | M4hnFLJ5XeP  | 30243414381012     | 2021-02-20 08:07:13 | China                 | Mongolian
  3 | Sephira    | Bayly     |  26 | sbayly2@rambler.ru           | INL57w6gXe   | 5100138794351466   | 2021-04-25 06:17:26 | North Korea           | Gujarati
  4 | Hermine    | Fassman   |  29 | hfassman3@smh.com.au         | 1UX4TApQMEuV | 3552094428434244   | 2021-06-18 06:48:54 | Indonesia             | Albanian