what should I do if I have 500$ each month to invest in crypto

I have about $500 each month from my salary. I watch some kols on youtube who suggest an average price strategy where I should buy my favorite coins every day for long term profit. Should I follow this, or is it better for me to hold USDT and wait for the dip to buy. (Honestly, I don’t even know where the dip is—like the current market, it just keeps getting deeper and deeper day by day