Nervous about flying out of the country with greencard

Hi everyone!

How likely is it for someone with a green card to be denied entry into the country? I received my green card less than a week ago, and I’m planning to attend my best friend’s wedding next weekend. Is it too soon to travel after receiving it? I have no criminal record, but I haven’t been able to travel for the last 6 years because my visa expired (not my I-20s so IVe been here legally the whole time). I'm feeling really nervous about going through border control. Is my concern justified, or should I be fine?

Thanks in advance!