Learn Romanian: Am destul timp. - I have enough time.

Unlike most Romanian adjectives which come after the noun, adjectives expressing quantity like destul (enough), mult (much), and puțin (a little) usually come before the noun, just like in English.

Does the word destul change depending on the noun?

Yes, when it is followed by a noun, it acts as an adjective and must match the noun's gender and number. Timp is a neuter singular noun, so we use the base form destul. If you were talking about a feminine noun like apă (water), you would say destulă apă.

If I want to say I have done something 'enough times', can I still use timp?

No, timp is only used for time as a duration or concept. When talking about occurrences or instances (like 'many times' or 'enough times'), you use the word oară (plural: ori). For example, de destule ori means 'enough times'.

Why is there no word for 'I' in this sentence?

Romanian often drops subject pronouns like eu (I) because the verb form already tells you who is doing the action. Am specifically means 'I have'. You only add eu if you want to emphasize that you have time, as opposed to someone else.