How long can I use OpenAI for free?

I've been hearing a lot about OpenAI and its capabilities, and I'm really interested in trying it out. But I'm also concerned about the cost, as I'm just starting out in this field. So, my question is, how long can I use OpenAI for free? Is there a limited time period, or can I access certain features without paying? I'd like to get a feel for the platform before committing to a paid subscription, if that's possible. Could you please provide some clarity on this matter?