Hi Christine. I agree with Patrice, although I have no idea what the para… nervous system is. Different things work for different people. There is no right or wrong way to meditate, in my opinion. Find what works for you. I started with guided meditation, then worked up.
What was hard for me in the beginning was I was obsessed with how much time had passed, how much time was left, etc. With a little help from the Angels, I found a piece of instrumental music that lasted for the thirty minutes I wanted to spend meditating, and that worked really well. I used music from the Calm app.
Also, i think it’s helpful to set an intention, or something you hope will come from meditating, like guidance on something, clarity, connecting with high Guides, love to the world, etc. Your mind will wander, and when it does, just gently set aside the thought and continue. A lot of people focus on their breathing, as Patrice mentioned, to refocus.
Lastly, I recommend keeping a meditation journal to record what thoughts you had, etc. Sometimes you can see patterns emerging. It’s ok if you fall asleep! I don’t lie down when I meditate for the same reason! I hope you get some useful info, and just keep experimenting with different things, until you find what works best for you. Blessings.