Looking voucher for Salesforce Certified Associate !

Hi Saee, In terms of vouchers access:

If you work for a registered partner you can ask them directly

Also staying tuned on potential discounts following challenges form trailhead(twitter) and the certifications days https://trailhead.salesforce.com/credentials/cert-days

Another option is start getting involved in the community events near your local areas, network and meet your peers, and learn a lot, and sometimes if you are lucky you may have a possibility to show your skills and earn one.