Query:
How do I track my Lead on the website and how will I identify the lead as user when he sign up to my webapp in Gainsight PX.

Explanation:

PX has two tags: 

1. Website tag --- “Tagkey-1”
2. WebApp tag --- “Tagkey-2”

Website tag should be configured on your website which will not have the identify call, where as Webapp tag will should be configured on your webapp which will have the identfy call

Behaviour/Process of Identifying the Lead and User

Please go through this Image that helps you with flow:

Thanks

Dileep Nalla