It is not appropriate for a man to not bring a gift when he meets the girl's parents for the first time, and it is not appropriate to bring a heavy gift. It is best to bring something practical so that the parents will think that you can live a good life and will not spend money recklessly, and then they will feel at ease to hand over their daughter to you.
Your girlfriend knows her family better than anyone else. She won't let you take wine, so don't take it. You can buy fruits, but don't buy some fruits that are everywhere in the market. Find some uncommon or difficult to buy, or buy more.
There are also real dolls and blessing chocolates. You can ask your girlfriend for photos of her parents, and then customize a real doll for marriage. It is very fashionable and individual, showing your thoughtfulness. It can also be chocolate with blessing words. You can think of the content yourself.
If you really have nothing to bring, you can bring red wine. It is healthy and beautiful, and a little wine can make you happy. If your girlfriend's family is not from the same place, you can also bring some specialties from your family. Such gifts are more thoughtful.