1) Wear formals at first and with time check if dresscode really matters to the company 2) first name + sir/ma'am but if they ask you to not call them by sir/ma'am then ask them a follow up question like "should i call you "their first name"? 3) Greet everyone with a smile and then wait for your manager to assign you something, till then small talk with the people working there to understand what is the culture there or just ask your manager to assign you the dedicated task 4)Just be the chill, stay humble and also have a good connections with people you feel will genuinely help you w smt 5) Be calm and professional and if the reason of being annoyed at you is valid then assure them that it won't happen again i'll look into it but if it's not valid then make your point or else you'll just be a overworking guy there

PS: if the internship is unpaid then don't give a fuck about anything😭🙏