Questions to ask my Congressman, TX-26, for town hall

Hello, my Congressman is finally holding a town hall this Saturday and I plan on going. This will be my first town hall and I haven't been more passionate about politics than I have been now and wanted to ask on DU what questions to ask. I do want to ask about investigations with Trump and his Russia ties, the Yemen raid and the ACA, but really don't know how I would phrase the questions. I want to be polite and respectful, but do want to call him out on any BS.

Any suggestions and advice is appreciated. Thanks!