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:
Testūdō, cum pedēs eius Lepus dērīdēbat, subrīdēns dīxit, “Sī perīculum in cursū fēceris, quis sit vēlōcior liquidō cōgnoscēs.”Ēlēgērunt igitur Vulpem, quae ambōbus et locum et terminum cursūs cōnstitueret. Testūdō, omnī sēgnitiē remōtā, iter arripiēns, haud quiēvit dōnec ad terminum pervēnerat. Lepus vērō, pedibus fīdēns, postquam paululum quiēvit, somnō excitātus, quantum pedēs valuērunt ad terminum cucurrit ubi, cum Testūdinem quiescentem reperit, sē fatētur ā Testūdine superātum.
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):
Testúdo, cum pedes eius Lepus deridébat, subrídens dixit, “Si perículum in cursu féceris, quis sit velócior líquido cognósces.”Elegérunt ígitur Vulpem, quae ambóbus et locum et términum cursus constitúeret. Testúdo, omni segnítie remóta, iter arrípiens, haud quiévit donec ad términum pervénerat. Lepus vero, pédibus fidens, postquam paúlulum quiévit, somno excitátus, quantum pedes valuérunt ad términum cucúrrit ubi, cum Testúdinem quiescéntem réperit, se fatétur a Testúdine superátum.
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:
Testudo, cum pedes eius Lepus deridebat, subridens dixit, “Si periculum in cursu feceris, quis sit velocior liquido cognosces.”Elegerunt igitur Vulpem, quae ambobus et locum et terminum cursus constitueret. Testudo, omni segnitie remota, iter arripiens, haud quievit donec ad terminum pervenerat. Lepus vero, pedibus fidens, postquam paululum quievit, somno excitatus, quantum pedes valuerunt ad terminum cucurrit ubi, cum Testudinem quiescentem reperit, se fatetur a Testudine superatum.
IMAGE. Here is an illustration for the story (image source).