Educating yourself about mental health is one of the best ways to help a friend. Reach out to those around you and check in regularly with a simple, 'how are you?' - it's the little things that can really help.
There are resources available that can help guide you on how to reach out and any signs you should look out for, these include:
Be mindful of those around you and check in on them whilst regularly checking in on yourself, too. It's important that you safeguard your own mental health and wellbeing when supporting others.