WhatsApp groups on new phone I upgraded to a new Android phone and plan to use WhatsApp on this phone with my old number. For the purposes of this question, I do not have my old phone with me, and do not have a chat backup (actually, my backup got corrupted somehow, long story, but let's assume I don't have access to any backup/history).
Now, this whatsapp account was part of several groups.

Is there any way I can send a message to those groups? Since my number didn't change, I should be still part of the groups but I don't see any.
If someone sends a message on that group, will I receive it on my new phone? (The same way I'd receive a DM from a single person who still has my old number)
Some of these groups required admin permission to send messages, which I previously had. Would I need to ask for that permission again?
backup got corrupted somehow dont worry
you just have to install whatsapp in your new phone and login with that old number you will get your old groups as it is dont worry just install whatsapp (its happen with me many times :)