It's fine, but it's always important to know what the movie is rated before going to watch it. These ratings often give you the general idea of the movie without giving away the plot.
G-rated: This means general. Anyone can watch this.
PG-rated: This means that parental guidance and supervision is recommended.
PG-13: This means that parental supervision and guidance is VERY recommended. Children younger than thirteen must have adult supervision.
R-rated: No one younger than seventeen may enter a movie with this rating. Adult supervision is extremely recommended in some cases.
NC-17: No one younger than 17 may enter a movie with this rating. No exceptions.
Anyways, @May_Otterview. I recommend that you always check the rating of a movie before watching it. They help you think twice about going to see it. Other than that, I also recommend always telling your parents what you're planning to watch. More often than not, they know A LOT more about the movie than you do and will give valuable advice or hold great insight as to whether or not that movie is good for you.
I hope this helps!