Honestly I wouldn't worry about blocking, if in doubt you can always block things quite lightly and then do it again if it wasn't enough!

I picked up a pack of kids foam play mats years ago, and use those as my unofficial blocking mats. Most things I wet block, but this one is acrylic so I did steam block it.

Pinned everything out onto my mats, held the iron about an inch away and just mashed the steam button! Not very scientific lol. Only thing to be careful of with acrylics is you can "kill" it if you get the iron too close, which is when it basically melts and loses all structure. Can be a cool effect for some projects!

Good luck with your bag and cardigan! Love to see people diving into bigger projects, they're really not as complicated as they seem!