Hi..I am also new to FMQ and I had real problems with my first quilt although my sample blocks were fine....I have since realised the following...
1. The Weight of the large quilt was so different it pulled and I pushed and it was really hard to get the quilt to move smoothly. I unrolled the quilt and had it all bunched up with it supported on the desk and my lap....this worked much better, just working on a small bit at a time and I worked from the centre outwards.
2. Tension...I had real problems because I choose King Tut thread which is lovely but I didn't realise you need to have the right needle for the cotton...but most importantly don't jerk the fabric otherwise the stitching will jump! Also I kept forgetting to put the dog feed down !
3. Speed...I had to go a totally different speed...this I think is personal choice and trial and error but it was really different from my sample blocks.
I have since gone on to FMQ three cot quilts and each time it is getting better, much neater and I feel far more in control....I think it is all about practice but doing a proper quilt is very different to small blocks
Good Luck...I keep reading on this board it is all about practice...practice...practice and everyone is right