Is it rude to show up to Shabbat late?

Hello, I’m a student studying Jewish Studies and I am going to Hillel for Shabbat dinner for the first time today. I’m wondering if it’s common for people to arrive late. I have to pick up my prescriptions before I go but I can’t until after 4:30 and Shabbat starts at 5:15. I have to take the bus and I know I’ll probably be late. I’m not sure what to do. I really need my prescription, but I also want/need to go to Hillel (need is bc I have a Judaic experience project and I’m using this opportunity to complete it). So is it normal or is it seen as rude to show up late?