“Opportunities” for photographers abound.
The thing to consider is the cost of that opportunity.
If the opportunity offers you no money to cover your expenses or time, then the cost of your opportunity is the wear and tear on your equipment, the cost of your expenses to get the work done and your time.
The cost of your expenses to get the work done and the wear and tear on your equipment is money out of your pocket.
The stuff you miss doing because you are taking the time to do non-paying or discounted work has a cost too.
This is time you could have taken to take paying work or to produce more meaningful work to add to your portfolio.
Choosing your opportunities are business decisions. Make sure that you choose wisely.