Latin pronunciation wasn’t static. Caesar’s pronunciation would have been different than the Latin you would have heard a few hundred years later when it became standard in the Church. That being said, you really have a couple of optionsYou can just use English sounds as you see fit. Most people will tend to do this.You can pick an era of Latin and try to use those sounds instead. Be prepared for people to not know what you are talking about though.If you elect the latter, here is a general guide:C is always hard (as in cake) in early Latin but probably had a CH (as in church) in late Latin and generally does in Church Latin in many words.G is always hard (as in gate or garden), but probably had a softer sound (like giraffe) in late Latin and generally does in Church Latin in many words.There is no J sound in early Latin and no letter J sin any form of Latin. Any place English puts a J in a Roman word, the Romans would have had an I and pronounced a consonant Y soundVowels for the most part sound like Italian (A, E, I, O U are ah, ay, ee, oh, oo). Except there is no letter U (see below). There are short versions of the vowels as well.U and W did not exist. The letter V was both a consonant and a vowel. The consonant form had a W sound in early Latin but changed to a V over time. The vowel form was the U sound as above.Latin has a lot of diphthongs, which are two vowel sounds that smudge together to form a new sound. AE is “ay”, AV is “ow”, AI is “aye”, OE is “oy”, EI is “ay”The Romans didn’t use the letter Y or the PH or PS combinations until they started importing words from Greek. There was probably a subtle difference in how they pronounced these 9since they didn’t simply use their own letters for these sounds), but you can just use a long E (as in knee) for Y, an F for PH, and an S for PS.There are some extra rules which affect how some letters are pronounced before what are called front and back vowels, as was brought up in the comments. Basically, in most European languages, consonants tend to be harder when they precede back vowels (gate, cop) and softer when they precede front vowels (gin, cell). Latin did this over time, and this is the main reason for the changes in 1 and 2 above.So…Gaius Julius Caesar (GAIVS IULIVS CAESAR) is “guy-oos you-lee-oos kay-sar”Augustus (AVGVSTVS) is “ow-goos-toos”Veni vidi vici is “way-nee wee-dee wee-kee”Antoninus Pius is “ahn-toh-nee-noos pee-oos”Marcus Aurelius is “mahr-koos ow-ray-lee-oos”The Catholic prayer Regina Coeli would have been “ray-gee-nah koy-lee” with a hard G in early Latin but is usually “ray-jee-nah chay-lee” in Church Latin.And my personal favorite - the short-lived and little-remembered emperor Pupienus is “poo-pee-ay-noos”. Yes, it sounds like Poopy Anus. History teachers no doubt rejoice that they don’t have to teach about him.