I need to understand mixing binaural beat frequencies


I’m new to binaural beats. Is it okay to mix binaural beats as you nap or sleep…i.e. Can I listen to :30 minutes (or longer) of alpha, then theta, then delta. Or is it meant to listen to one frequency over and over. Also, is binaural better than isochronic and can you mix them. Also, how effective is solfeggio and Shumann resonances? I just get stressed and have insomnia and looking for the proper procedures. I know that’s a lot of questions, but this is all confusing to me. Thanks!