My machines aren’t fussy so I can use any thread I like for the most part. I did try Madeira cotton embroidery thread for free motion quilting but it wasn’t strong enough. Right now I am using aurifil for piecing
regarding free motion quilting most people have your experience on their first try. I did. But I didn’t stop, I kept going. I had a dinky mechanical machine from Costco but I learned to do free motion quilting on it.
if you decide to try again one day check out the free tutorials on Leahday.com.