It is no big deal. I have been playing for some time and at maximum level but I missed out on the Gateway prize as well. I am just busy at work and with my kids and underestimated the time. Now in Act 2, we have adults helping get gummies, I was able to get the tenta HQ prize. Just have to play efficiently. Time it when the kids are done with S'mores. Make sure you do the daily House of Evil quests.
When I started, it was the Stonecutter Event. The Stone Cutter lodge was my fourth building. I had Simpsons house, Ned's house, and a brown house. I really didn't know what was going on and didn't have most of the characters to get much prizes. Just a bunch of stonecutter walls. Much later I got the Daycare Center for free from the mystery box.
It's tough, but there is plenty more events as you grow your town, money and experience. I built lots of houses to gain cash and exp. I put them in every nook and cranny I can fit. Hide them behind bigger buildings and have several blocks of houses. Don't bother with the brown houses too much. Just have one or two because many characters interact with a brown house.
TRy to build as much wailing walls and spooky walls. None of this is real. So just have fun.