Hi, I have some interesting advice, we are all no better than each other, there is only one master.
I hope you can find some value in it
Probably shouldn't go into the meditation thinking stuff like "OK I am going to meditate now I better not screw up" That won't help you.
You don't need to "do" anything really all you are doing at the most basic level is just allowing yourself to "BE". Don't attach anything else to it.
Slow and relaxed breathing does help to gradually decrease the amount of thoughts, you shouldn't monitor yourself too much just allow yourself to let go and put your focus on your body relaxing each muscle fully, it will all come with practice, as I said I am no master.
Here are some ideas for you all to look at, regardless of where you are there may be something you may not have thought of.http://www.esotericenergy.com.au/freetipsandadvice.htm
Have a rad day, Peace