Should I be concerned that I only see "Out" connections, and not "In" connections? What does this mean? Is everything fine, or is there something I'm doing wrong?
Bitcoin Core does allow inbound connections by default, but it does not advertise its own address during the initial synchronization. So if you just started running Bitcoin Core and have not caught up to the chaintip yet, that may explain why you are not seeing any inbound connections yet.
Another common reason is that your network configuration blocks access to Bitcoin Core’s port from the internet, and you may need to open the port on your router for your node.
Finally, you may have explicitly configured your node to prevent inbound connections via
--nolisten if you followed some guide that was aiming to reduce your bandwidth usage.