The salad fork and the soup spoon. The wine glass and the water glass. The napkin in your lap.
All the rules and rituals of proper etiquette will certainly serve you well. Such knowledge is admittedly in short supply at present.
More important, though, are manners, as it takes very little learning to master them, but a great deal more diligence to practice them consistently.
You may know the protocols, but without sincerity, your elegant exercises will fall short.
With manners that spring from common courtesy, you may not know it all, but you will be forgiven by those who can see that you endeavor to extend kindness to all.
Manners are a mindset. Adopt that first. Open a door for someone. Offer your place in line.
Smile. Be interested. Listen.
Then study etiquette.