Avoid going insane. Everything else is detail. Naturally there are challenges and such things create rules. It helps to pay attention to them.
For most, the first hundred years is an orgy. It is downhill from there. By your first millennium you better get used to the fact that civilisations rise and fall faster than flooding of the Nile. They have their endearing moments for sure (who didn’t love the baths?) But in the end, they leave you in their dust – a sanity denting experience. Accept each for what they truly are: another preening ignorant Ozymandias.
There is a lot to avoid. Avoid instantaneous gratification like Britons and other people who didn’t bathe. Avoid puns about having all the time in the world. Eventually you’ll get used to seeing mountains reduced to hills, seas drained and rivers forgotten but there’s no need to rub it in. More importantly, PLEASE avoid trying to be clever with Greco-Bactrian jokes in Mayan. So many have tried and created nothing but the most awful silences at dinner parties.
Getting along with the rest of our crowd is a necessity and need not be tedious. Tactful frankness is desired. Nobody will tell you when your Sumerian has been neglected to the point of acquiring a 6th dynasty camel trader’s accent. Eventually you’ll notice that they know you know that they know. The conversation will continue to flow without a beat to the reflection of the moon on the pond. The view accompanied by Haiku as perfect as the wine.
Good conversation is the only currency that’s portable across the ages. Become refined in the art of its performance, proficient in maintaining its freshness and wise in your appreciations of it. A process similar, yet thankfully faster, than the birth of a diamond.
Thankfully you can’t rush to master such things. Even if you are lucky to get some help from DuFu. Live at the pace of glaciers and drink lots of clean water. Know that only the first thousand years are the hardest. Try not to go mad till then.