Can I create a SQL query in Airtable?

You cannot directly query an Airtable table, but you can use a view to accomplish the same goal. The best way to think about translating queries to Airtable is that each view contains (roughly) the output of a query on a single table.

A SQL query, or a query written in any other database interfacing language, is a way to pull and filter information using certain parameters. Building a view you can apply the same kinds of parameters (sorting, filtering, grouping) to filter and present the information you'd like from your base's tables.

When building a view you can filter  through your records, hide any unnecessary fields, group values, and sort values as desired.
You can also add additional formula fields to handle complicated conditional logic to use in a filter.

You can join multiple tables together by "hard coding" joins into a table using linked record fields.  With linked records in place, you can then effectively perform subqueries using lookup and rollup fields.

With your view, your "query", created it is automatically saved on your table. You can easily switch between views, building new views on the fly, and know your "query" will be there for reference whenever you need it.