Is there any way I can get a free subscription?

The Basic account gives you free access to create 5 activities, which includes deleted resources.

You can also use hundreds of games on the community page without being charged. Creating more than five activities requires a paid subscription (Standard or Pro).

Though it is not technically a free subscription, some teachers coordinate with their schools to buy a school plan so they don't have to pay for it.

See: Where to get copies of my invoice/receipts?

How to get a school plan?