There are so many options for cutting out your printable designs. You can use a paper trimmer for straight lines and scissors for more intricate objects. If you plan on creating party printables, get a 2” round hole punch for cupcake toppers and gift tags. It's a minimal investment that will save you hours of time, and your hands will thank you. Also, check out the hole punch aisle at your local craft store for more options.
Adobe Illustrator is the best option because graphics are vectors, meaning you can size and resize your images without making them pixelated. You can create poster sized images or cake toppers with the same graphic and the quality of the graphic won't be affected.