Perhaps you have started with Azure DevOps, or have commenced with defining your Azure Pipeline in YAML.
When running a hosted agent there are few problems you will likely come across, apart from the consumption of minutes.

There can be some issues when you define a new pipeline, particularly in YAML, when using a self-host agent.

Here’s an excerpt of an Azure Pipeline, using a self-hosted agent:

name: $[variables['build.number']]

trigger:
  batch: true
  branches:
    include:
      - master
  paths:
    exclude:
      - terraform
      - pipelines

pool: AgentPool01

stages:
- stage: WebApp
  jobs:

One of the issues you may come across is when you run the Pipeline that the job is waiting ‘endlessly’ to be queued. Something like the following:

You may find one of these two options will help:

  1. Update the Agent

You’ll find this by navigating to Project Settings -> Agent Pools -> Open your Agent Pool -> Choose the Agents tab -> select the Agent options (3-dots) -> choose Update Agent

Alternatively, you can also choose to Update all agents.

2. Check Agent Pool Pipeline Permissions

The more likely fix will be that the newly defined Pipeline does not have sufficient privileges to use the Agent Pool. To check and enable this setting,
you’ll find this by navigating to Project Settings -> Agent Pools -> Open your Agent Pool -> Choose the Security tab -> enable Grant access permission to all pipelines