Select rows from my table where a character column matches a pattern
Use a regular expression:

SELECT *
FROM   tbl
WHERE  name ~ '^\d+ .+';


The regular expression explained:

^ .. start of string
\d  .. class shorthand for digits
+ .. 1 or more of the preceding atom
 .. plain space
.+ .. any character, again 1 or more of those

There are many different characters that look like a space. ' ' is just the plain space character. You might want to use the class shorthand \s instead to cover all of them.