I completely understand how you feel too, Ellie.

And I would want to rip it back and start again, so that it was all my own work

. So I think I would do as Sally suggests, and have one that
is all my own work, and one that I practise on, and make mistakes on!, and take to the knitting class

What I am wondering is whether there is some tutorial you can find that will teach you all these stitches and techniques on an exercise piece. Have you had a look at Craftsy, and KnittingDaily? As well as the classes and videos you have to pay for, both have quite a few free eBooks and videos. KnittingDaily does have a 'Lace Knitting' eBook, which I think probably does have simple scarf patterns to get you started.
When I did my first 'fancy shawl', I ripped it back no end of times. Each time I re-did it, the bit I had done before got easier... so in the end I just decided to not mind
how many times I re-did it, it was all learning. And by the end of knitting that shawlette, I was very comfortable reading lacework charts, finding those stitch patterns in my knitting, dropping sections to fix a stich 5 rows down and re-forming using a crochet hook - so it really had been worth it.
But I did use lifelines when I got to the end of each section and was confident I had it right

. If I were you, I would use lifelines, and leave them all in, so if you do end up at the knitting group with someone wanting to rip back again, you can tell them 'only to the 3rd lifeline' - and then after they've helped you, if you feel you should, you can rip back to the 3rd lifeline again and re-knit the section you've been working on.

You
are making progress, so don't give up. You'll get there. And you'll feel
so proud of yourself when you do!
