Parsing  Scroll down,or click on linked line numbers. 
( Line 1 ) ( Line2 ) ( Line 3 ) ( Line 4 )( Line 5 ) ( Line6 )

Line 1
Militat
   3 singular present indicative active; subject is amans
 

omnis
   nominative singular masculine
 

amans
   nominative singular masculine; translate as amator
 

habet
   3 singular present indicative active; subject is Cupido
 

sua
   accusative plural neuter
 

castra
   accusative plural neuter
 

Cupido
   nominative singular masculine
 

Line 2
Attice
   vocative singular masculine
 

crede
   imperative singular present active
 

mihi
   dative singular masculine; dative with special verbs
 

militat
   3 singular present indicative active
 

omnis
   nominative singular masculine
 

amans
   nominative singular masculine
 

Line 3
quae
   nominative singular feminine; the antecedent aetas follows
 

bello
   dative singular neuter; dative follows habilis
 

est
   3 singular present indicative
 

habilis
   nominative singular feminine
 

Veneri
   dative singular feminine; dative with compound verb convenit
 

convenit
   3 singular present indicative active; subject is aetas
 

aetas
   nominative singular feminine
 

Line 4
turpe
   nominative singular neuter; predicate adjective: understand est
 

senex
   nominative singular masculine
 

miles
   nominative singular masculine; in apposition to senex
 

turpe
   nominative singular neuter; supply est
 

senilis
   nominative singular masculine
 

amor
   nominative singular masculine
 

Line 5
quos
   accusative plural masculine; the antecedent animos follows
 

petiere
   3 plural perfect indicative active [alternate form of petiverunt]
 

duces
   nominative plural masculine; subject of petiere
 

animos
   accusative plural masculine; object of petiere
 

milite
   ablative singular masculine; object of the preposition in
 

forti
   ablative singular masculine; modifies milite
 

hos
   accusative plural masculine; supply animos
 

petit
  3 singular present indicative active; subject is puella
 

socio
  ablative singular masculine; modifies viro
 

bella
  nominative singular feminine; modifies puella
 

puella
  nominative singular feminine
 

viro
  ablative singular masculine; object of preposition in