More about Infobox League - Template:NewInfobox_Season
This is an example for a Tournament page, click edit and copy the actual wikicode to start working on it.
For an example of a good page for a smaller/weekly tourney, check Sleek's_5v5_Tournament, Lawbringer's_3v3_Tournament.
For an example of an extensive wiki page for a large tournament - check North_American_Spring_4v4_League(2020), Intercontinental_Regimental_League.
Required minimum information: filled out infobox and sections: Format, Prizepool, Results
Some basic one-liner about the tournament can be placed at the very top of the page.
Location: Only specify that if event is physically hosted in some country (a LAN for example), or it is a country specific online tournament. Specifying that an offline event is held in Poland or USA when it's actually open to everyone just does not make sense.
An explanation of the tournament's format (single/double elimination, round robin, qualifiers etc.)
Provide a prize pool template
You can find all kinds of bracket templates and examples here: Category:Brackets.
Not always needed
Not always needed.
An example 8 person bracket is below, there are many more brackets and examples on the Category:Brackets.
You can include only a section of the bracket, and provide a link to the full bracket hosted somewhere else.
External links go here.
Provide links to Stream/VOD links, interviews, etc. Someone might come across the page later to edit or add something. Make it easier for them to find sources.
You can copy the contents of the greyed out section below, and use that as a starting point for a tournament page.