Learn Italian: Il bricolage, ovvero il lavoro pratico, è molto utile. - DIY, namely practical work, is very useful.

While ovvero can act as a formal word for "or" (like oppure), it is very frequently used as an explanatory marker meaning "in other words," "that is to say," or "namely." Here, it introduces a clarification for the term il bricolage.

Could I use cioè or vale a dire instead of ovvero in this sentence?

Yes, absolutely. Vale a dire, in altre parole, and cioè all serve the exact same function here. Ovvero and vale a dire give the sentence a slightly more formal, written tone compared to the everyday conversational cioè.

Bricolage is a French word. How do we know it takes the masculine article il?

Italian has adopted several French loanwords, especially for hobbies and concepts. Foreign loanwords that do not end in a standard Italian vowel are almost always assigned the masculine gender by default, which is why it becomes il bricolage.

Since the sentence mentions both il bricolage and il lavoro pratico, why is the verb singular (è)?