Is it okay to pair garlic cheesy bread on lemon zest chicken? What else dish to add?

A lemon chicken is both classic and almost neutral in its flavors, so you could pair almost anything with it...green vegetables (broccoli etc.), orange vegetables (sweet potato etc), a bread to mop up sauces or a starch like risotto yo balance the meal.
The only thing I'd avoid is mixing cuisines in the side dishes. Lemon chicken could work with various European or Asian cuisines (e.g., French or Thai) but only one at a particular meal.