The main thing you need to do is realize you are not in the West anymore, that you are going to have to adapt to the lifestyle and combat style of the Kurds. Most people take for granted how difficult that is to do every minute of every day for months at a time embedded with a foreign people with whom you can only partially communicate in an extreme and desperate combat situation.
Instantly you will be suspected of being a coward, being weak, being effeminate, being sexually degenerate(there will be women around, this matters), being rich and spoiled, ect ect. Most westerners are in and out of Syria in two months, the Kurds are used to white men with big smiles who run at the first sign of adversity.
Living condition: Prove to them you can eat with your hands, shit in a trench, go weeks or even months wearing the same pair of clothes. Weeks or months without electricity, which means no contact with the outside world. Never miss guard duty unless you literally can't stand. Never go to the doctor unless you are approaching serious medical emergency. I was there five months never once saw a doctor, I was ill for weeks at a time. You will be seen as weak for asking to see a doctor, being sick is just part of the soldiering life in this area of the world.
Women: Speak to women politely and show only enough interest in them as not to be rude. You wont find true fucking love there, I've seen plenty of guys think a smile from a gorgeous 19 YPJ girl means something. YOU ARE IN THE MIDDLE EAST! If you so much as try to hold hands with a YPJ girl they will boot your ass, but more importantly she may end up in jail and almost certainly out of YPJ. On the other hand don't go to far in ignoring them, I failed to shake hands with three beautiful YPJ girls on the front lines once because I had a policy of basically pretending women didn't exist. One of them stood up stormed over and chewed me out for several minutes for disrespecting her(she was a commander.) These women run the gambit from atheistic communists to Islamic Kurdish Nationalists, I could go deep into the contradictions in Kurdish society between its communist theory and its Islamic/traditionalist past and the strange hybrid culture that has emerged as a result, but this post is already way to wordy. Suffice to say its difficult to adjust to the nuances. If you remember one thing about the YPJ, remember women are fighting and dying, any Western "white-knight" bullshit is seen as MASSIVELY insulting. Rightfully so. Generally avoid them.
Combat: This is probably the easiest for civilians. The combat here has absolutely nothing to do with modern western military theory or practice. At all. Whatsoever. Most ex-military guys don't last. They are used to eating McDonalds in the greenzone and having the entire might of the American military behemoth behind them at all times. The thing that will shock you the most is the Kurds willingness to die in battle and their condescension regarding medical treatment of injuries. You are dealing with a war hardened and radicalized segment of an oppressed society that is on the verge of victory in a millennia long struggle for freedom. They will die willingly to achieve this, everything is secondary to the cause.
Miscellaneous: Don't show sympathy for the Arabs, it will get you nowhere. Don't bother supporting Jews or Turks either, you will only be ostracized. Don't defend dogs or animals in general from abuse more than is absolutely necessary. They simply don't have the same cultural beliefs involving animals and pets, I told my Kurdish friends my dog sleeps in my bed and they were disgusted and highly amused. Don't, DON'T try to rescue puppies who are starving or thirsty or alone ect ect. You are passing a death sentence on them, the best chance they have is that their mother is out of sight. The kurds will just kill a dog out of hand if it becomes inconvenient. Before you get on your high horse remember what American mass meat industries are doing to animals.
In closing just keep your head down and your mouth shut. Make friends, this is the best way to see combat. Work hard, and watch out for copper wires on the ground. Remember, you will change nothing, you will convince no one. Observe, it will be the most insane experience of your life, in a very good way if you have gravel in your guts and spit in your eye.