Learn Hardcore German: Der Absender steht oben links; die Bestellung ist noch offen. - The sender is at the top left; the order is still open.

In German, printed or written items (words, labels, addresses, prices) typically use stehen to indicate where they appear on a page or sign: Die Adresse steht oben links. You could say ist to express existence or state, but for layout/location of text, stehen is the idiomatic choice. Other options:

befindet sich (more formal/neutral: Die Adresse befindet sich oben links.)
liegt describes objects lying on a surface, not printed text, so it would be odd here.

What exactly does oben links mean? Can I also say links oben?

Both oben links and links oben mean “top left,” and both are natural. You’ll hear both orders in practice. To be more explicit, you can say:

in der linken oberen Ecke = in the top-left corner
Other positions: oben rechts (top right), unten links (bottom left), unten rechts (bottom right), in der Mitte (in the middle), am rechten Rand (at the right margin)

Do I need any punctuation or a hyphen in oben links?

No. oben links is a simple adverbial of place—no comma or hyphen. If you turn it into an attributive phrase before a noun, you still don’t need a hyphen: die oben links stehende Adresse. Hyphens are not required here.