Hi LC. Remember that all spiritual paths have differences of activities and philosophies. Witchcraft is just another spiritual path, and then within that path are many traditions and practices
. The author(s) that you're reading and whose advice you are following subscribe to self dedications before practicing witchcraft, year and a day learning, and perhaps that one must have two patron gods, as well.
These practices are common to paths such as various forms of Wicca, for instance, but they are not a necessity in all witchcraft paths. In terms of self dedication, some might say that just working on a spell is one's way of showing dedication to one's craft/path, and that that's the only self dedication that's important really, no ceremony needed.
It is my experience that if you don't do any of those things, it will not bar you from working spells and doing other witchcraft activities successfully, any more than it would bar you from painting a painting say, or cooking a recipe in the kitchen, or playing a song on a guitar. In fact, spell working is very akin to cooking ...there are ingredients to use, which get combined in some way, and an end product of some sort is obtained.
Spell working, painting, cooking, music...these are all creative processes, making you yourself a bonafide Creator Being. Do we need permission or patronizing from other beings to create what we want to create? In fact, some people find it rather insulting to be "patronized," by a god or another human being. It's all just physics really, manipulating subtle energies and dense matter on different levels. Are we not entitled to access these energies (as much as any god) because we are our own sovereign beings?
This is just another perspective I'm sharing with you, and not in any way putting down the aforementioned popular pagan practices. In the end, you will select which practices and principle are relevant to you, and which are not.