I’d say the biggest thing you can do is start educating yourself on this illness. There are many facets and symptoms and things that can easily turn into something big.
There are negative and positive symptoms. Cognitive abilities get affected, so does memory.
Many meds come with huge side effects and people don’t always stay med compliant, not because they don’t want to be better, but because the meds feel worse then the disease.
The more you know, the more you can help him. Also, please start looking around and getting to know what resources are in your area, what treatment centres are bad and good.
The more you know, the more you can help. The more you can also help yourself.
Get some support for you as well. I ended up in a sibling support group and it was exactly what I needed. Ideas and resources started coming our way when we knew what was out there.
It’s not always easy, but it’s possible to get through this.
Also, remember to hang out with your loved one and leave the SZ chat on the shelf once in a while. My brother hates it when all the conversation is about his illness.
The list of what you need, can feel huge.
Good luck and I hope you and he both get support and kindness.
Welcome to the forum.