Another thing that is easy to do on a Mac with no extra software is to use clip art.
I have several clip art books from Dover Publications. They come with a CD-ROM
I usually use the JPEG format. I copy the image I want to my Desktop and drag and drop it into Pages ( which is Word on a PC)
From pages I resize it to any size I want. I don't need Vector graphics to do this.
I just did a card with Clip Art from Dover in my Gallery . I resized it to fit the oval I wanted to use .
Birthday Silhouette by Barbara Jay - Cards and Paper Crafts at Splitcoaststampers