I used the pattern in this book I often do make my own patterns, but I didn’t have the time or energy. I did get the book through Amazon used in good condition, and it looked new when I got it. But if you go that route be careful because I got a different book used and there were none of the pattern paper inserts anymore. But this is a fun book and I will definitely use other projects.
I also lengthened the capes for my kids.
If you can afford it, I would take some private lessons with a teacher. If not, look for classes. If you live near NYC or LA, Mood Fabrics has been offering free six-week classes for children (separately) and adults.
I would buy a good book such as the Reader's Digest Guide to Sewing (old editions are fine) or The Sewing Book by Alison Smith. I would also look for a good book on teaching children how to sew. You can do the projects along with your daughter.
For more advanced projects, I would look at a book like Oliver + S Little Things to Sew: 20 Classic Accessories and Toys for Children.
In the first year, you should do sewing machine exercises for control, learn some seam finishes, commonly used hand stitches, and how to install a zipper. Use only cotton. Make a muslin practice garment before sewing real fabric. Place the emphasis on doing neat work instead of being fast. If you're quick but sloppy, it will be hard to advance as a sewer.
The great thing about children's clothing is that you can make basic shapes in bright prints and colors and it looks great without buying 40 different patterns.
I think Made by Rae has nice basics for childrens. Most of her patterns come as PDFs which need to be printed and assembled.
If you like twee, I'd go with the book by Oliver+S, it has clothing, not just accessories and toys.
My most favorite children's patterns are from Ottobre Design, their 1/2021 issue has loads of basics. Sewing from magazines is not for everyone, the patterns come on big sheets with overlapping lines and have to be traced, and the instructions are minimal. It comes from Finland, but there is an English version and shipping is free.