Welcome to Algorand!
Currently, each creator can only create up to 1000 ASAs.
So you may need multiple creator addresses.
One thing you may want to take care is avoid filling up completely blocks as it induces congestion fees.
So you may want to restrict yourself to creating 100-200 ASAs per block, that is 40 ASAs / second.
If you were creating tens of millions of ASAs, you also most likely want to optimize the way you query the node: it is more efficient to first post all the transactions for a given block, then wait for the next block, and only then check one by one that the transactions are posted, rather than naively post and wait for confirmation.
I think the most important point would be to follow ARC-3 to be future-proof: