Sons first birthday ideas!

My sons first birthday is at the end of January. Thankfully it’s on a Saturday so we can celebrate it on the actual day. I’m kind of stumped as to where to have it, what theme we should do....I wanna do something unique. He loves Shrek, Trolls, Gnome Alone & Scooby Doo. I would like to make the theme something like that...That leaves me with not knowing where to have the party. Since it’s in January I can’t have it outside. Our house is a duplex & isn’t really big enough for all the people I’m wanting to invite. Their won’t be any room for him or the other kids to play...I’d like to have music that matches the theme of the party. So I’d like to have music, plenty of room with something for the kids to do. Give me some ideas that’s not crazy expensive! I plan on getting the decorations offline so hopefully it’ll be cheaper then going out buying everything individually.