Hey Praveenkumar! Congrats on the ACE certification!
If you're after more structure around using the sandbox starter toolkit, and further your Aviatrix certification journey, I'd suggest taking a look at the Infrastructure-as-Code course/cert. This will get you working with that sandbox starter environment, as well as introduce you to the powerful automation capabilities of Aviatrix by leveraging Terraform.
Currently, the cost is around $10USD (using the discount code ACEINFRASTRUCTURE) and is self-paced. I feel it would be a great next step in your Aviatrix certification journey while giving you that guided hands-on experience it seems you're after.
Good luck with your training!