Use a vlookup function in B$6$ to locate total Sales for whatever tree may be listed in A$6.$ Remember, your table is in A$5$:D$10$ on the Summary sheet. $($Your result will be #N$/$A for now because we have not selected a tree yet for A$6.)$ Format B$6$ to currency with $0$dec. Resave.

Use a vlookup function in C$6$ to locate No$.$ Sold for whatever tree may be listed in A$6.($Your result with be #N$/$A$.)$ Format No$.$ Sold to number with $0$ dec. Resave.

Create a validation list for $A6$ on the documentation sheet that references the trees listed on the Summary sheet. Make up an appfopriate Input Message and Error Alert. Test the data validation in A$6$ by selecting a tree from your list. If your vlookups are correct you should see values appear. Resave.