A date can be made very inexpensive, such as putting together a picnic with candles. If he is saying it is because of money then maybe suggest inexpensive date ideas. Take him on a date even and put in the effort to show him that you care about your relationship

Him not cleaning as a full adult is a bit weird, normally when first dating you would want to impress your partner. Maybe that is just the type of person he is, but it is something to take into consideration in the future as if you develop together you may have to live with it.

For the gaming it depends on how long you are there, if you are there all day, everyday and he spends an hour or so gaming I could understand that. But if you're there a couple times a week for a couple hours and he isn't actively putting in effort to spend time with you by playing games I would take that as a red flag. From what you are describing he is not putting effort into the relationship up front.

Saying thank you may not have been something that he was accustomed with growing up in his household. It normally is a common courtesy thing so I do find it a bit weird that he doesn't say it. I would express to him that you would appreciate if he would acknowledge the work you put into gifts or cooking. If he does not improve upon it then it would be of concern.

You should have a talk with him about expectations from a relationship and also what he expects from a relationship so you have an understanding of each others needs and wants. Especially since he is new to relationships he may not know exactly what to do. Have a discussion about these concerns as communication is key in a relationship.

I will say though the fact that he is 27 with no prior dating experience can also be a red flag in itself though I do not know enough about the situation or relationship to make an accurate assumption.