Purchasing our first TT - is this set up safe?

Hi and welcome! That's a mighty big trailer for starting out. Leaving the #s to others to sort out, but I would be looking around the 26' - 28' max with your current tow vehicle. Rule #1.....NEVER take the salespersons word for anything. You need to do plenty of homework....your MB dealer can be a big help, always welcome to ask any questions here, do lots of online research re capacities. With good research, you'll come up with the right combo and be heading out for some great times. Enjoy!