Congratulations on finishing your PhD, getting married, and getting hired as a lecturer, all at once!
Can you record the first lecture online? We've all been pretty used to online lately, so maybe you could start the class off this way. Apologize to the students, explain you're out of the country but everything will be normal for week two. You would probably need to clear this with your department first, but this seems like the best option if they'll allow it.
Barring that, has your school opened up the fall classes for student enrollment yet? If not, maybe you can shift the weekly schedule to get another day or two. I see August 23rd is a Monday - does that mean you teach M-W? If so, maybe you can switch the class to T-Th, for example.
Or if neither of those, are you teaching one section of a larger course, with other professors also teaching the same sections with standard curriculum? This often happens for early required classes that many students take every year. If that were the case, maybe you could ask one of your fellow instructors to cover your first class, because they will have prepared the exact same material already anyway. It's a little awkward since you're asking favors of people who don't know you, but it seems reasonable.
If none of those alternatives work, unfortunately, I think being back on the 22nd is your only option. A teaching schedule isn't flexible - students sign up well in advance in order to coordinate their schedules, and the semester itself starts on a university-wide schedule that everyone knows well in advance. You want to make a good, professional, first impression with the department and your students, and not taking responsibility for being there on the first day of class would be quite the opposite.