Here's a step-by-step guide to activate your Disneyplus.com/Begin account:

1. Visit the Disney+ Website:
Open your web browser and go to the official Disney+ website: Disney+.

2. Click on "Sign Up":
Locate and click on the "Sign Up" or "Start Free Trial" button.

3. Choose a Plan:
Disney+ offers several subscription plans, including monthly and annual options.
Select the plan that best fits your preferences.

4. Create Your Account:
Fill in the required information, including your email address and a strong password.
Click on "Agree & Continue" or a similar button to proceed.

5. Billing Information:
Enter your billing information, including your name, address, and payment method.
Some regions may offer a free trial. If so, you might be required to enter payment information but won't be charged until after the trial period.

6. Review Your Order:
Review the details of your subscription, including the plan and billing information, to ensure everything is correct.

7. Click "Start Subscription" or Similar:
Once you're satisfied with your choices, click on the button to start your Disney+ subscription.

8. Verification Email:
You may receive a verification email at the address you provided. Open the email and follow any instructions to verify your account.

9. Set Up Your Profile:
After verification, you can set up your profile. This might include choosing a profile picture and setting parental controls if applicable.

10. Download the Disney+ App (Optional):
If you plan to watch on mobile devices or streaming devices, download the Disney+ app from the App Store (iOS) or Google Play Store (Android).

11. Log In:
Open the Disney+ app or website and log in with the email and password you used during the sign-up process.

12. Start Streaming:
Once logged in, you can start browsing the content library and streaming your favorite movies and shows.

Remember to keep your login credentials secure and, if needed, set up additional profiles for family members under the same account. The steps might vary slightly based on your region and updates made to the Disney+ sign-up process since my last knowledge update in September 2021. If you encounter any issues, refer to the Disneyplus.com Login/Begin help center or contact customer support for assistance.