what to do

I am new at gardening, I have Parsnips in tubs and some in a small patch, My garden is 10mx10m, lawn in center, 4mx6m, so not alot for growing , lots of pots ,Ihave just lifted my dalias , stored in a tub with shreded paper, we had a frost last week ,upper Port glasgow, so i cut everything back , lillies, herbs, tomatoes, courgettes, too soon??. 

Have you dried the dahlias off?

Tomatoes and courgettes wil not come back -compost them.

Why did you cut everything back? Lilies will die back on their own, and can then have the dead foliage/stems removed.

Many herbs are hardy and should be left alone, e.g., bay, parsley, rosemary, sage, thyme.

BW Parsnips are sweeter after a frosting, many roots are left in the ground unless it becomes too wet then lift them put them in Washed sand in a cool place.
If you lift Dahlias put them in boxes with a covering of sandy soil or peat, stems down to drain any moisture and keep an eye on them, they too want to be in a dry cool place, a garage or shed. After a while I turn them upright in the box and cover with more sandy soil damping them very slightly, in spring you divide the tubers and plant up in pots to bring on.
I cut my herbs back in Autumn and the new growth soon shows though this year because they are now old I have taken some out and will replace them with cuttings taken earlier.
New or old gardeners we are always learning so ask if in doubt, someone out there will know.

Frank.