Our company uses Moodle and WooCommerce on our WordPress site. We also use MailChimp for email campaigns, but have found the program is not easy to use as a CRM. We were looking into CRMs that are compatible with Moodle, but that may not be a requirement. We are looking for a CRM that does the following:
1. Multi-user access with differing levels of access, ie. basic users, manager who can see their own contacts and the contacts of the basic users, and a sys admin who can see everything
2. The ability to store individual notes regarding each communication with a customer or potential customer
3. The ability to schedule future communications, ie. “call again in two weeks” gets put on a To Do schedule
4. The ability to store multiple phone numbers, email addresses, and mailing/billing addresses for a customer
5. The ability to store multiple customer contacts for a individual company
6. Customizable fields – we may want to store a customer’s time zone or associate a particular customer with a basic user in our company
7. Being able to set default values for certain fields, ie. for a particular basic user, his/her name is automatically assigned to a particular customer
8. Currently, we are using MailChimp to schedule email campaigns. A CRM that can do this task instead of using MailChimp

I recommend you use a dedicated, purpose-built CRM product like Salesforce or Hubspot rather than MC or a WordPress plugin.
I have been using Funnel Whirl and am really happy with it! 💯
[Funnel Whirl])