Hello Emil, and welcome to the B&R world!
To get connected, you’ll first need to know how the IP address was configured in Automation Studio. The settings in the project you transferred would have overwritten anything that was already there. To see this, go to your Physical View, right-click on the Ethernet port, and go to Configuration. Can you please tell us what you see here?
The default setting is for the controller to get its IP address from a DHCP server. If it is not connected to one, then you can change this to “Set IP Address Manually” and enter an IP address and subnet. I also recommend setting SNMP to Activated for now. This will allow you to browse for the controller via the Online→Settings Browse window in Automation Studio if you forget the IP address.
To diagnose the Service mode, there are a handful of helpful posts on the Community about how to collect diagnostic information, such as Service Mode - What is it and how to collect diagnostics - Share Info & Ideas / How-To & Wikis - B&R Community and PLC module stuck in “BOOT mode: Service” - unexpected reboot and connection issues - Ask Questions / B&R Software & Runtime - B&R Community. Please take a look at the Logger once you get connected and let us know what error messages you see.