Salaam from a local officer – need advice

As-salamu alaykum, everyone. I’m a patrol officer in California, and there’s an Islamic center in the area I cover. It’s a masjid where about 50 to 100 people gather for prayers very early in the morning and also in the evening. With the recent attacks on places of worship, I want to be proactive and park outside the mosque to help deter any trouble. So far, I’ve been sitting out front in my marked patrol car, in uniform, windows down, just waving at folks as they come and go. I want to show that I genuinely care and am interested in building a connection. Is it okay if I say *As-salamu alaykum* with my hand on my chest? Which hand? What other simple phrases can I learn? Any customs I should be aware of? Forgive me if I’m missing something obvious-this is all from a sincere place. JazakAllah khair in advance. – a friend.