Learn English – What does “I gotta go” mean

The meanings are essentially the same, although "going into" makes it sound like the match is coming up very soon or immediately, while with "heading into" it might still be some time away (like a few days).

To "kick off" means to start. It can be transitive or intransitive.

The phrase originates in sports, like other answers have said.

In contrast to what another answer says, the actions that are started can be either positive or negative.

For example, a big project at work could have a "kick off meeting" where the people working on it are introduced and the goals are discussed.