Begin by cloning the GitHub repository that contains the data you need. Use the `git clone` command followed by the repository URL to download the repository to your local machine. This allows you to access the data files directly from your local environment.

```bash
git clone https://github.com/username/repository.git
```

Navigate to the cloned repository directory and identify the data files you wish to move to TiDB. These files could be in various formats like CSV, JSON, or SQL dumps. Extract these files to a working directory where you can process them further.

```bash
cd repository
ls # To list files and directories
```

Open each data file and ensure they are formatted correctly for import into TiDB. For CSV files, check for consistent delimiters and header rows. For JSON, validate the JSON structure. If SQL dumps are used, ensure the SQL syntax is compatible with TiDB.

```bash
# Example command to validate and format a CSV file
csvtool check file.csv
```

If you haven't set up TiDB yet, you can either install it locally or access an existing remote instance. For local installation, follow the official TiDB installation guide to get a working instance. For remote access, ensure you have the necessary credentials and network access.

```bash
# Example command to start TiDB server locally
tiup playground
```

Before importing data, define the database schema in TiDB. Use the SQL `CREATE DATABASE` and `CREATE TABLE` commands to set up the necessary tables matching the structure of your data files. Ensure the schema accommodates all data types and relationships.

```sql
CREATE DATABASE mydatabase;
USE mydatabase;
CREATE TABLE mytable (
id INT PRIMARY KEY,
name VARCHAR(100),
age INT
);
```

Use TiDB's built-in tools like `LOAD DATA` for CSV files or manually insert data using `INSERT INTO` statements for smaller data volumes. For JSON, use a script to parse and insert data. Ensure the data types and formats match the schema you created.

```sql
LOAD DATA LOCAL INFILE 'file.csv'
INTO TABLE mytable
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\n'
IGNORE 1 ROWS;
```

After importing, verify that the data in TiDB matches the original data in GitHub. Run SQL queries to check row counts, data types, and sample data entries. This ensures that the migration process completed successfully and data integrity is maintained.

```sql
SELECT COUNT() FROM mytable;
SELECT FROM mytable LIMIT 10;
```

By following these steps, you can successfully move data from a GitHub repository to TiDB without relying on third-party connectors or integrations.