Q: How to fix "Illuminate/Database/QueryException with message 'SQLSTATE[42S22]: Column not found: 1054 Unknown column"? I have created model which name is project

php artisan make:model project

and then using php artisan tinker tried to add a record into it.
In command line when I run:

$project = new App\project;
$project->title='My first project';
 $project->save();


It shows this error:

Illuminate/Database/QueryException with message 'SQLSTATE[42S22]:
  Column not found: 1054 Unknown column 'title' in 'field list' (SQL:
  insert into projects (title, updated_at, created_at) values
  (My first project, 2019-01-11 06:46:09, 2019-01-11 06:46:09))'

It doesn't perform $project->save(); and gives this error. Please help.

A: No migration performed
php artisan make:model project

This is the fault which I believe you do not have a migration file created (refer to Future Reference section below why I said so), since the error stated that the column is not found.
To better solve this, I suggest you create a migration file as follow:
php artisan make:migration create_projects_table

You can see inside database/migrations, there is a new file with the name 2019_01_11_153037_create_projects_table something. The time and date is different from yours, but the main focus is 'create_projects_table'
Inside the migration file, you can see there's up() function. Copy this code
public function up()
    {
        Schema::create('projects', function (Blueprint $table) {
            $table->increments('id');
            $table->string('title');
            $table->timestamps();
        });
    }
}

Finally, perform a migration, and you should see a migrated success message.
php artisan migrate

Future reference
In the future, to save time, you can create a model together with its migration, as follow:
php artisan make:model Project -m

Notice the -m tag, which creates a migration file for you. Afterwards, proceed with editing the migration file (e.g., add columns to it as demonstrated previously).
Learn more about Laravel's migration here: https://laravel.com/docs/5.7/migrations
One additional notes, check out Laravel's convention on Eloquent Model so that Laravel can perform it's magic:
https://laravel.com/docs/5.7/eloquent#eloquent-model-conventions
Your project model should properly be Project
Edit
If you have performed a migration somehow before, then run a different migration (there's no limit to how much you can make migration).
php artisan make:migration add_column_title_to_projects_table

And there's a new migration file created. Inside the up() function, add this code:
public function up()
{
    Schema::table('projects', function (Blueprint $table) {
        $table->string('title');
    });
}

Finally, perform php artisan migrate

A: You have to try this:
 $project = new Project;

 $project->title = $request->title;

 $project->save(); // it will INSERT a new record

Updated Answer
$project = new App\Project;
$project->title='My first project';
 $project->save();

