Time to farm loot boxes. You have until March 3 to open loot boxes and get a toy train, the first multi-hero mount. It’s a must have, although I’m not sure it’ll be in ranked play (we’ll see). There is no tips to farm, just open loot boxes. It’ll come sooner than later. It seems to have a reasonable drop rate, although as always, it can be harder for some over others.
You can find more out about the event here: https://news.blizzard.com/en-us/heroes-of-the-storm/23227139/the-toys-are-back-in-town-heroes-of-the-storm-2019-winter-event-details
That’s all there is! The Toy Train can be ridden by multiple players, so it’s a strong tool in maps where you want everyone to move together at the same time. Although, it makes being ganked as a team far more likely, it can help keep everyone together at the very start which is what matters in a lot of games.
You’ve got three months or so to farm, so no big deal, but be aware that the mount is really good considering the unique mechanic.