READ OUT LOUD. Choose which marked text you prefer to practice with - macrons or accent marks - and read the text out loud until you feel comfortable and confident. Then, try reading the unmarked text at the bottom. It should be easy for you after practicing with the marked texts. :-)
MACRONS. Here is the text with macrons:
Leo, audītīs rānae clāmōribus, prīmum animō valdē perculsus est, quod crēderet ingentem animantem auctōrem esse tantī clāmōris. Animō sēnsim firmātō, circumspicere, et contrā illum clāmātōrem, quisquis esset, sēsē parāre, et ad pugnam accingere. Cum autem videt prōrēpentem rānam dē propinquō lacū, ibi leo, simul indignātiōne simul etiam pudōre affectus, pede illam conculcātam attrīvit.
ACCENT MARKS. Here is the text with ecclesiastical accents, plus some color-coding for the words of three or more syllables (blue: penultimate stress; red: antepenultimate stress):
Leo, audítis ranae clamóribus, primum ánimo valde percúlsus est, quod créderet ingéntem animántem auctórem esse tanti clamóris. Ánimo sensim firmáto, circumspícere, et contra illum clamatórem, quisquis esset, sese paráre, et ad pugnam accíngere. Cum autem videt prorepéntem ranam de propínquo lacu, ibi leo, simul indignatióne simul etiam pudóre afféctus, pede illam conculcátam attrívit.
UNMARKED TEXT. Here is the unmarked text - after practicing with the marked text that you prefer, you should not have any trouble with the unmarked text:
Leo,
auditis ranae clamoribus,
primum
animo valde perculsus est,
quod crederet
ingentem animantem
auctorem esse tanti clamoris.
Animo sensim firmato,
circumspicere,
et contra illum clamatorem,
quisquis esset,
sese parare,
et ad pugnam accingere.
Cum autem videt
prorepentem ranam
de propinquo lacu,
ibi leo,
simul indignatione
simul etiam pudore affectus,
pede illam conculcatam attrivit.
IMAGE. Here's an illustration for the fable (image source) showing a puppet theater with a lion and a frog:
