WhtasApp problem with the new smartphone. help!

Hi, I don't have much smartphone experience and I have a problem with Whatsapp because I'm not an expert.
I was using WhatsApp in my Huawei Honor 9 very well, but yesterday I bought a new smartphone the Samsung S20 FE and I moved both the SIM card and the SD card from the old smartphone to the new one.
But now I have 2 problems with Whatsapp:
1) All chats have been deleted and I no longer see them on my new Samsung, even though I see all the contacts on Whatsapp.
Can I recover the chats since I also have the old Huawei too?

2) In the Address book, which I had saved on Google, I now see all the contacts but I don't see if they have Whatsapp. Why please? Before, I could write on Whatsapp directly from the contact name. In fact there was a Whatsapp green icon, but now it's gone.
I am very sad. Can I solve?
Thanks