Hi Bhushan,
Step 8 has - "Management Groups, Log Analytics Workspace & Custom Policy Definitions" as prerequisites and this step creates policy assignments to the Management Group Hierarchy and also assigns the relevant RBAC for the system-assigned Managed Identities created for policies that require them (e.g DeployIfNotExist & Modify effect policies).
https://github.com/Azure/ALZ-Bicep/wiki/DeploymentFlow#module-deployment-sequence
Log Analytics workspace can only be created inside subscription. So, if you do not have a Subscription, then you cannot continue with Step 8.
Also, there are steps before step 8 for role assignments which would be needed for policy assignments to happen. Without that step 8 could fail with permission errors.
Even the intermediate ones will not be possible without step 4.
As a workaround, you can try passing a dummy log analytics workspace as parameter and try the policy assignments at step 8 but chances are very low that it would work.