Interview etiquette

People who have given an interview in the past, how do I conduct myself in there and what to wear(Male). Also, can I bring a laptop inside to show my projects ( I have a portfolio and projects in GitHub but to run it you need a certain environment which needs to be set up).
I am a Fresher.

Business formals is ideal for interviews. In my experience I have seen candidates coming in casuals since most companies here are start-ups.
I recommend formals for F2F interviews, if you know that on a particular day there is only written/coding rounds, then you may wear casuals.

I think GitHub is enough to showcase your projects. You can explain them and show them the code there. I don’t recommend laptop since in many companies it mentions not to bring any electronic devices.