The administrator of your AWS account should have your AWS Access Key and AWS Secret Key stored somewhere safe. If you can no longer find them, you can create a new pair of keys via the AWS console under the My Security Credentials section of the AWS console, which you can access by clicking the dropdown next to your name in the top-right.
AWS Console > My Security Credentials > Access Keys > Create New Access Key
To connect Retool to Athena, you need to know the Query result location. You can find this via the Athena section of the AWS console, by clicking on Settings.
AWS Console > Athena > Settings
Create a new resource in Retool, and select "Amazon Athena" as the type. Enter your AWS credentials and Athena query result location into the "Athena" datasource form, and press "Save".
Resources > Add > Amazon Athena
You can now select your newly-created Athena resource from the Resource dropdown when creating queries in your Retool apps.
You can display the results of Athena queries as with any other query in Retool:
Athena queries are slightly different to normal SQL queries, however — in addition to having a
data key, they also have a
queryExecution key that contains metadata. This might be useful to keep an eye on since AWS charges you according to the amount of data that's scanned when executing the query.