This poem is from the proverbial distichs of Georgius Carolides (1569-1612), which you can read online at the University of Mannheim.
Omnium Rerum Vicissitudo Est
Quicquid ages, finem coepto praepone labori;
Fine bono totum nobile fiet opus.
The vocabulary is keyed to the DCC Latin Vocabulary list. There is only one word in this poem that is not on the DCC list:
praepōnō, praepōnere: place in front, prefer
vicissitūdo (vicissitūdinis, f.): change, alteration
agō agere ēgī āctum: drive, do, act
bonus -a -um: good
coepī coepisse coeptus: have begun
fīnis -is m.: end, boundary
fīō fierī factus sum: become
labor -ōris m.: toil, exertion
nōbilis -e: distinguished, noble; (as subst.) a nobleman or woman
omnis -e: all, every, as a whole
opus operis n.: work
quisquis quidquid: whoever, whichever
rēs reī f.: thing (rēs pūblica, commonwealth; rēs familiāris, family property, estate; rēs mīlitāris, art of war; rēs novae, revolution)
sum, esse, fuī: be, exist
tōtus -a -um: whole, entire