The order that works

1
Log into your personal Facebook account

Meta requires one to create a Page. If you don't have one, create it first.

2
Create the Page

On a computer: Menu, then Pages, then Create new Page. Enter your business name and category, add a short bio, and click Create Page.

3
Add your profile image and cover photo

Use your logo or a clear photo. Fill in contact details and hours.

4
Create or find your Business Portfolio

Go to business.facebook.com and make sure the Page sits inside the portfolio you own.

5
Switch Instagram to Business or Creator

Instagram, then Settings, then Account, then Switch to Professional Account.

6
Connect Instagram to the Page

Instagram, then Edit Profile, then Page, and pick your Page. Then check both show up in Business Suite.

Only you can do: identity verification and your business verification. Nobody else can complete those for you.
Don't: create a second Page "just to test." Extra Pages and portfolios are the most common reason people can't find their real one later. See Find Your Real Meta Business Portfolio.