Palette knives are great for mixing paint. I made one painting using only palette knives. As a newbie what surprised me is that they are not all the same. I use metal palette knives. Some are springy and too soft and too bendable and others are so stiff that they might as well be a thick butter knife, which to me is not good. Then there is the size and width which varies.
These are the type of little things that you must learn by experience. What you need for your own usage and style of painting will vary from what others prefer so hearing the opinions of others sometimes do not help.
If you jump into learning to paint you will learn lots of things by hands on experience that can never be prepared for and decided upon by thinking before doing. I understand the desire to save money and buy only the exact right supplies before you begin but that desire is just not possible for some art supplies. As you use things that do not work or are inferior quality it gets to a point when you just decide that a poorly working tool is too big a hindrance or a hassle, and the investment in a new better thing is truly worth it. Even when we are talking about a $3 palette knife, because art supplies start to add up!
I use a few at a time for paint mixing to allow each to remain dirty with paint, one for each major color scheme being used (blues, greens, grays or whatever I am focusing on at the time). I also use one designated for scooping out my acrylic gel medium.
P.S. I find packs of wooden handled metal bladed palette knives at discount at Tuesday Morning sometimes. If you have a chance to touch them in person in a fine art store I recommend that, after you know what it is you like and dislike.