Struct Vs Class for Array Element?

Question

Happy Thanksgiving everyone! I am very new to C#. and I made a class to store info about
media files. I need a  "structure" to hold start and end positions of certain media files. Some
media files may need 20+ sets of "start" and "End" data and some may need only 1 for the
enire duration. So what is the best way to do this. So far I have:

 namespace UsefulPlayer
{
    [Serializable]
    class MediaFiles
    {
        public string FilePath { get; set; }    //Path to file
        public string FileTitle { get; set; }   //Title w/o path
        public int FavoriteLevel { get; set; }  //Sortable attribute:Favorite
        
        public struct Markers   //Clips: each media file can have multiple
        {
            float StartPoint;
            float EndPoint;
        }
        
        //Constructor
        public MediaFiles(string MediaFilePath) 
        {
            FilePath = MediaFilePath; //Path of file <-- Passed in
            FavoriteLevel = 50;       //Default to 50. 1=Sucks! 100=Great!
            
 
        }


    }
}

Since those two variables (StartPoint and EndPoint) are so closely related to each media file I don't
want to create a seperate class for them. Should I make a list/array/collection of these structs, or
should I use something other that structs all togeather. From what I have read I should avoid structs and make a separate class but the two variable are tied closely to each media file and each media file could require multiple sets of the variables so what to I do? As I said I am a newbie so forgive my
ignorance. And thanks in advance to everyone for your patience and knowledge.  =)