DNS query on self hosted site

Depends what you set in the DNS records and where you published them? Literally no idea tbh.

Have you purchased and are using a public domain? Or is it just self-hosted DNS within your LAN?

If it's a publicly registered domain, they'll get the same thing you will: the IP you've set in your DNS records. If that's a local ip (192.168.x.x, 10.x.x.x) it'll be useless. If it's your public IP, well it points at your router and someone can use it to try and connect to you. Unless you've forwarded ports, that connection will likely fail.

If you've only setup local DNS, someone outside you network will either get nothing back from querying your domain or, if the domain you've chosen also happens to have a public counterpart that you don't own: they'll get an IP unrelated to you.

Selfhosted... at home? If i would run a DNS query, i could see your IP