Start by exporting the data you need from Asana. To do this, navigate to the project or workspace you want to export. Use the "Export/Print" option generally available in the top-right menu of the project view, and select "CSV" to export your data. This will download a CSV file containing your Asana data to your local machine.

Open the exported CSV file using a spreadsheet application like Microsoft Excel or Google Sheets. Review the data to ensure that it is formatted correctly. Clean up any unnecessary columns and ensure that the data types (e.g., date, text, numbers) are consistent and match what is expected in Teradata.

Ensure you have the necessary credentials and network access to connect to your Teradata database. Use the Teradata SQL Assistant or any SQL tool that supports Teradata, and establish a secure connection using your database credentials (username, password, and host address).

In Teradata, create a table that matches the structure of your CSV file. Define the column names and data types to match the data you have prepared. Use the following SQL syntax as a guide:
```sql
CREATE TABLE asana_data (
column1_name data_type,
column2_name data_type,
...
);
```
Replace `column1_name`, `column2_name`, and `data_type` with the actual column names and data types you need.

Move the CSV file to a location accessible by Teradata. This might involve uploading the file to a server that Teradata can access, depending on your organization's infrastructure. Ensure that the file is in a location where you have read access.

Use the Teradata SQL Assistant or BTEQ (Basic Teradata Query) to load the CSV data into the newly created table. You can use the following command format:
```sql
.IMPORT VARTEXT ',' FILE='path_to_your_csv_file.csv';
.SET RECORDMODE OFF;
INSERT INTO asana_data VALUES (?, ?, ...);
```
Replace `path_to_your_csv_file.csv` with the path to your CSV file, and adjust the placeholders `?` to match the number of columns in your table.

Once the data is loaded, run SQL queries to verify that the data in Teradata matches the source data from Asana. Check for discrepancies in row count and data accuracy by running queries like:
```sql
SELECT COUNT(*) FROM asana_data;
SELECT * FROM asana_data WHERE conditions;
```
Address any issues by revisiting the earlier steps and adjusting as necessary.

By following these steps, you can effectively transfer data from Asana to Teradata without relying on third-party connectors or integrations.