> In creating a new table, how is primary key set to begin at a value other than 0 or 1?

"begin" suggests that you plan on some form of auto-incrementing a
value for the primary key field?

If so, I'd say you'll need a generator anyway.
You can set this generator to any (valid) value you like, but you
should always be aware that especially setting it to a lower value
than before can mean a lot of trouble.

Here's the syntax for Firebird 2.5

ALTER SEQUENCE <Generator_Name> RESTART WITH <new_Value>