LDAP is not a prerequisite for ADCS. If your company uses ADDS, then you have the option to deploy a Enterprise CAs to simplify certificate issuance and deployment to users and computers.
If you do not have a AD domain, then you install Standalone CAs.
That is why your approach makes no sense. You would not install ADDS on server2 only to run an intermediate CA.
There are many ways how to set up a PKI infrastructure, and it seems you should read up on that topic, to get a little understanding of how to achieve your need. I suggest you start with this guide: https://techcommunity.microsoft.com/t5/ask-the-directory-services-team/designing-and-implementing-a-pki-part-i-design-and-planning/ba-p/396953
But to answer your question: Join server2 to the same AD domain as server 1 and install an Enterprise Subordinate CA. If you plan on having your Root CA online (which I assume), then it should be an Enterprise Root CA.
However, if you plan on implementing a multi-tier PKI your root CA should be standalone and offline. You also should never install a CA on your domain controller. And your CDP and AIA locations should be on an HTTP server only, optionally also deploying an additional OCSP server.
In small businesses where certificate are required only internally, you could get away with installing a single Enterprise Root CA and also use LDAP as your CDP and AIA locations.
I strongly suggest you read up on the article, if you plan to put your PKI to production.
