Congrats! For the in person interview my best advice is to avoid acting embarrassed or defeated if you do stutter. Stop, smile, excuse yourself and start again. If you show the interviewer that you have difficulty but have accepted it and are not defeated by it, it will say a lot more than if you seem embarrassed or self-conscious. To deal with a difficulty head on and appear determined shows maturity and perseverance, which is what any employer wants to see in a candidate. Acting shy or embarrassed can make you seem more weak and not as mature which I don’t need to explain is not the image you want to go for. Good luck!