The "toss" that is mentioned must be a coin toss/throw of some sort that decides which team starts on which side of the pitch/field in a sport. The "first half" is the first half or beginning period of whatever sport is being discussed, perhaps rugby like you mention.
The "play into the elements" part of the quote has to do with weather "elements" like rain, wind, sunshine, etc. The speaker is implying that since they lost the coin toss they are at a disadvantage because they will have to start play facing into, or in the direction of, the wind or perhaps with the sun in their eyes.
Does that make sense?