Where can I buy measurable data tokens?

I'm interested in purchasing measurable data tokens, but I'm not sure where to start. Could you please provide some guidance on reputable exchanges or platforms where I can safely and securely buy these tokens? Additionally, are there any specific factors I should consider when selecting a platform, such as fees, security measures, or the availability of the tokens I'm interested in? I'd appreciate any insights you can offer to help me make an informed decision.