I got my first moderna covid shot and had no problems. now time for the second, is there any reason to expect the possibility of problems with the second if there was no problem with the first?

The second vaccination is associated with more local and mild side effects such as redness and soreness at the site. The vaccine is recommended unless otherwise contraindicated.

Different people will manifest different immune responses and symptoms from the vaccine, however bear in mind 100'' of millions have been given with major side effects extremely low and much lower than that of Covid. That said, I'd say most people have more symptoms after the second dose and a higher immune response. As a cardiologist I do advanced cardiac imaging and any vaccine issues is rare.