This little poem comes from Disticha de Educatione of Urbano Appendini, published in 1834; you can see the whole book at Google Books.
Inter mille unum cautus tibi delige amicum;
Delectum nullis desere temporibus.
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:
cautus, -a, -um: cautious, careful, wary
dēligō, dēligere: pick, choose, select
amīcus -a -um: friendly; (as subst.) friend
dēserō -ere dēseruī dēsertum: leave, desert, abandon
inter: between, among; during (+ acc.)
mille (pl.) milia: thousand
nūllus -a -um: not any, no one
tempus -oris n.: time
tū tuī tibi tē: you (sing.)
ūnus -a -um: one