Now is the perfect time to fix one thing, he can eat or not.
He will not starve himself, he won't. He will learn he can manipulate you with not eating to get what he wants, that happens early on. Do not cater to him, offer choices, and though some frown on it, dessert is my biggest bargaining tool. It is very simple, you eat what is served or nothing else most certainly NOT dessert. With two one of whom eats anything and everything, the other follows suit as there have been many nights my son watched my daughter eating her ice cream and he got none.
Hold firm, he will not starve, offer milk after or during dinner, limit snacks a few hours before the meals so he is truly hungry. Have him try before he ever says "I don't like this or refuse it" that drives me batty, my friend let's her four year old dictate every meal and say "I don't like it"..without ever even trying it.
My son hated fish, especially salmon, I made it and would put one bite on his plate, he would not happily eat it, but ate great veggies and whatever else we had, now after probably 20 times, he loves it!
Continue to expose him to new flavors and foods, he is to eat two to three bites or nothing else!
Be tough, a few nights of him being hungry before bed he will get it! Promise, it is not mean, but teaching good eating habits. He is still young so making sure if he really doesn't eat to give him a Pediasure or a multi vitamin.
My friend had trouble since day one with her daughter and continues to cater to her and she is four and just as stubborn as before, she will it only 10 things and does not try anything new or eat anything else and my friend tolerates it! If you want the battle to stop, then you have to be willing to put in the work, it isn't easy, but stick with it.