It's really not that hard. Here's the key points from that article, but please do read all of it and protect yourself with advance knowledge:
Black Friday do’s and don’ts
Do:
Only buy from brands you know and trust
Check URLs match official retailers’ sites
Look for contact details and return policies
Ask yourself if you’re feeling pressured
Keep your software up to date
Check your bank and credit card statements regularly and keep an eye out for suspicious transactions
Double-check offers on official retailers’ sites or apps.
Don’t:
Click on links from ads or emails – enter web addresses manually
Pay by bank transfer – always use a trusted payment method like a debit or credit card
Shop on social media
Respond to requests on text or email for additional information or to pay further charges.