Tuition tax credits? (Ontario) confused how they work..

I’m wondering if anyone knows how these work? I have about $13,000 provincial and $9000 federal in tuition tax credits. How much does this mean I will get back? How much was yours and what did you earn back? I’m wanting to purchase my first home and already have a bit saved up for a down payment..wondering if should use my current credits to help or just save them (not done school yet).