First Punjabi conversation with my in-laws: how to handle the 'formal' vs 'informal' trap?

I have my first major family dinner coming up where I'm expected to use Punjabi. I’m terrified of accidentally using the informal 'tu' instead of the respectful 'tusi' or messing up the honorifics. Are there any specific phrases I can memorize to bridge the gap if I get stuck, or is it better to stick to simple, short sentences to avoid accidental rudeness? I really want to make a good impression without looking like I'm reading from a textbook.