Yeah, the conjugation alone tells us that you're saying 'I read'. It would also be OK to translate 'Leo' to that, as well.
3rd of singular ends with "e" when the verb in infinitive ends in "er" or "ir". For example, ir you have the verbs: leer, escribir and comer, that will be:
Él / ella = lee, escribe and come.
But, like English, there are irregular verbs. So, in Spanish we learn the conjugations of basic verbs like "to be", "to write", "to know", "to love", "to go" that have normal or irregular conjugation. Then, when a verb have the same end in the verbs in the conjugation, a teacher, professor or anybody who teaches, say "this verb conjugates like "that" verb".
When you have to learn a new verb, you have to see a conjugation chart to know how conjugate th verb, you have too see it before you learn it, this is how we learn Spanish in school, so, don't worry, all Spanish speakers have to live that :P