I already have an annual pass that expires next month. If I renew it now, can I get access on a blockout date?

I am wondering if I renew an annual pass 30 days early I can get access on a blockout date. Some of the family's passes have expired, and I understand if they buy new ones they can use those on a blockout date, but I am wondering if I can do the same for renewing? If not, can I just buy a new pass and forget the 30 days left on the current one?

In a word, no.

If you renew an annual pass, you are still subject to the blockout dates. And no, you cannot just buy a new pass and "forget" the old one. They use your driver's license for ID, so unless you have a second driver's license (which I hope you don't), then it won't work.

The way you can get around the blockout dates is to buy a TICKET on a blockout date after your pass expires. Then take the ticket and upgrade it to a pass. You'll get credit for the ticket price, and you are good for that one day.

Annual pass for what, please?

Assuming you are referring to Disneyland, the Obviousman summed it up. If it's not for Disneyland, you're on your own!