Welcome to the community!
We did an article that you may find helpful, this will guide you on how to track your NBN service installation. How to track your TPG service installation
Once the NBN service installation is complete you may proceed on setting up the equipment or the modem/router. You may check this guide.
We recommend the best thing to do first is check if there's an outage on the NBN network.
We have created this article that can guide you on How to Check for NBN Network Outage
If there are no known outages in your area you may perform basic troubleshooting, we did an article that you may find helpful see this link below.
Should you need further assistance, feel free to search community for help or chat with us at https://www.tpg.com.au/support/contact/ and we'd be glad to assist you.