There are going to be plenty of good players available at 21. Looking at consensus boards, the most likely to go in the top 20 are:
DE: Hutchinson, Thibideoux, Walker, Johnson, Karlaftis
OT: Neal, Ekwonu, Cross, Penning
CB: Stingley, Gardner, McDuffie
WR: Wilson, London, Williams, Olave
DT: Davis
LB: Lloyd
S: Hamilton
QB: Willis or Pickett, maybe both.
We should therefore have the following to potentially pick from: Andrew Booth, Dax Hill, Kair Elam, Zion Johnson, Devonta Wyatt, Boye Mafe, Kyler Gordon, Nakobe Dean, Treylon Burks, Kenyon Green, Lindebaum. If two QBs go in the top 20 it will push another player down from that list.
So plenty of corner and trade down options, just don't expect a receiver. I'm personally fully on the Dax Hill train.