Setting Up Google Maps
To use the Maps module, you'll need to create a Google Maps API key.
Google has made this much more complicated recently and Google Maps now requires a payment profile in order to use their service. However, unless you have a very high-traffic site, you will likely fall within their free tier.
Their pricing is free up to 25,000 map loads per day, then $0.50 USD / 1,000 additional map loads per day thereafter.
To get your API key:
Go to Site Settings > API Keys and follow the link in the Google Maps API Key info box.
Click Get Started in the Google Get API Key link.
Check all three boxes to enable the Google Maps Platform, then click Continue.
Select an existing project, or create a new project, then click Next.
If you created a new project, you can name it whatever you'd like, then click Next.
Now you'll create a new billing account. Again, you will get 25,000 daily map loads for free. Click Create Billing Account.
Agree to the Google Cloud Platform terms and click Agree and Continue.
Create a new payment profile, or choose an existing payment profile.
You will be prompted to create an API key - click Next.
Finally, you have your API key. Paste that value into Site Settings > API Keys > Google Maps API Key (shown in Step 1)
You can now use the Maps module.