48 years old, currently have no investments. My net worth is my car and the clothes on my back, and I don’t ever want to be in this situation again.

(Edit: I don’t need to buy a house or anything whatsoever related to a house, so please don’t mention the “h” word in your response, it’s triggering me for tangential reasons. Let me be clear, I will NEVER care about real estate whatsoever, mmmkay? Just trust me when I say I have a roof over my head and it’s completely paid off, no property taxes, and No, I will never sell it, so the whole h-word" aspect of life is not a concern for me, k?)

Just looking for guidance where to invest this relatively small amount of money every month so in a few years when I’m older & frailer I’ll have enough for retirement. I don’t want it to just sit in my bank account, I want it to grow.

For reference, I’ve been living on approx $1500 per month for as long as I’ve noticed, so I don’t need much per month, and the sooner I die, the less retirement fund I’ll need, but we can never predict when anyone’s death will happen, so let’s assume I’ll live to 100 because I’m ridiculously healthy & an exceptionally good driver, never been in an accident, one speeding ticket in my entire life, no social life so I never get into risky situations, so let’s just plan for the possibility I’m going to live another 50 years.