I wear glasses have since I was 11 and never use straps or anything even jump in them sometimes. But normally if I am jumping, doing any faster or more likely to bail stuff I do wear my contacts. But on a whole I normally just ride in my glasses never really had a problem if your glasses have been fitted which should be done when you collect your new glasses that should be all that's needed.
Be prepared to break some, we have all had sunnies broken I'm sure glasses no different hehe I have face planted with them on, had a horse knock them off my face with his knee then fast like lightening he stood on them.
But yeah welcome to the world of blind you will get used to it all and will become more confident about wearing them!