Please mention your Magento Version first.
An exception was raised while creating "Request"; no instance returned
Your First error is coming due to most likely not changing php version properly, you should only use PHP version 7.2 when you're working on Magento 2.3.x
Change PHP version according to your Magento version, refer below link
if you're using Magento 2.3.x
Try below commands for changing PHP version
sudo a2dismod php7.0
sudo a2enmod php7.2
sudo service apache2 restart
sudo update-alternatives --set php /usr/bin/php7.2
Also refer this link for similar issue
Magento 2.2 with PHP 7.1.9 Issue
About your second error regarding 7.2 version,
Try to give permission first to your Magento Directory
sudo chmod -R 777 magentoDir
then use your upgrade-deploy commands.
if that doesn't help try to find solution in below link.