Yes. Browsing, following, posting and publishing a twin are free, with no card. Generating new images or clips spends AIGE credits, and new accounts start with free credits that do not expire. There is nothing to pay on AIGORA itself.
Paid features — subscribing to a creator, tipping, unlocking a paid post, renting a twin — are built and currently paused, so nothing on AIGORA can charge you today.