Migrating an Magento 2 site comes with its own lot of troubles, for example, you end up with your site, but without styling. Run trough the following steps to get it back up and kicking.
Step 1 - Double check db credentials in env.php, im sure you've done this right, but just do it.
Step 2 - Login to Mysql and go core_config_data: table
and change web/unsecure/base_url and web/secure/base_url values to the right urls.
Step 3 - Delete cache stuffs:
php bin/magento cache:flush
Removes all items in the default Magento cache (var/cache) and the var/full_page cache that have a Magento tag.
php bin/magento cache:clean
This command removes all items in the cache. This is the equivalent of deleting the entire contents of the cache folder on the server.If your system uses an alternate cache location, any cached files used by other applications will be removed.
rm -rf pub/static/frontend pub/static/adminhtml var/view_preprocessed var/cache
Step 4 - Then run upgrade, compilation and static content deploy :
There's a chance it started working correctly now! so now is the time to check, still not working, then here's a few additional tips:
a ) Change Files / Folder permission ownership
chown -R www-data:www-data ./magento-folder
b ) Are your SSL settings correct? (secure url is https:// for example)
Still not working? leave a comment below or contact me ;)