Both your internal and USB adapters can be made to work. Let's try the internal one first (remove the USB adapter and keep it removed while trying the internal one).
With a wired connection, please run the following commands in a terminal -
One or both of the second and third commands may return error (like "no such file.." etc.), just ignore if they do, and proceed with the next ones.
sudo apt-get purge bcmwl-kernel-source
sudo rm /etc/modprobe.d/blacklist-bcm43.conf
sudo rm /etc/modprobe.d/broadcom-sta-common.conf
sudo apt-get install linux-firmware-nonfree
Reboot and see if you can scan and connect to the wireless networks now. If you can, let me know if you need to troubleshoot the USB one also.