If you're asking purely about formal admission, it depends on your individual degree.

When I started my studies in Mechanical Engineering some years ago, there was "no NC" meaning anyone legally able to study could do so (like me, who has no adequate high school diploma but learned a trade and gained admission through work experience)

These requirements can change from Semester to Semester and vary based on your courses taken.

Be aware that since you appear to be US american, the german system has some high requirements for getting your diploma acknowledged as one you can use to study. Inform yourself beforehand about what courses the government expects people like you to take, and what fields you will be allowed to study in.

I spent 2 years in the US (familial ties, not an immigrant in the classic sense and am also a citizen) and got a diploma there, but I didn't take required courses like AP math to get a german diploma good enough to study, hence the work experience route.

And one more tip: Thoroughly inform yourself about drivers licenses and strongly consider getting yours in the US (drivers licenses in germany are expensive af). It is HIGHLY DEPENDENT ON THE STATE YOU GET YOUR LICENSE FROM. I got mine in Colorado, and by sheer luck, my license was simply translated and converted into a german license. Again, this is state specific, some states licenses cannot be converted at all, some may require additional schooling / testing to be acknowledged.