This Ex. 74 by Czerny op. 599.
But near the end of the first bar I play the 16th notes B and C?
I can tap the B with thumb,
and the following C just means go back to trilling D and C but start with C to begin it?
As you can see the trill between cd ends before the two 16th or better said the latter bc are included in the trill.
If you start the trill with d it will be easy to perform with 16th notes. If you begin with c (as written) there will be a triplet before the two last 16th.
You can practice both version, this is not so important.
You can also perform the passage in triplets or any duplets, don’t count to much, just let it flow, nobody of the audience will count the notes but they will hear and see when you are counting and struggling.
Paul Czerny 1830