While that's very true that these questions have been asked and answered here it is sometimes difficult for beginners to decipher between the good stuff and utter nonsense (especially when "knowledgeable" members get their facts munked up...happens to the best of us). Fortunately these are very simple questions for the most part so allow me to try shedding some light here for you, Necro.
Astral travel is by personal definition just means to explore the astral planes in some manner. You can use one of various forms of projection, remote viewing, etc...
Projection means that some part of your conscience has temporarily separated (metaphorically speaking) from your physical body. By metaphorically I mean this is not a physical split nor are the two pieces completely separated, there will continue to be some kind of sympathetic connection unless unusual/abnormal happens.
Minions is a vague word used a lot by beginners. The closest thing I can think of when it come to what people expect out of minions are thoughtforms or servitors of some kind. Thoughtforms are beings of your accord created out of focused energy and energy programming. They can be programmed to perform specific tasks.
Spirit animals are spirits representing you by taking symbolic, animalistic forms. They aren't typically of any specific type, spirit animals can be bother earthly or metaphysical.
"Grimoire for the Apprentice Wizard"...never read it but I hear it's interesting .
Magic names can be either be chosen or given. If you belong to a group, coven, cult, whatever...they might provide you with one. Some people even get them from spirit guides or what-have-you but otherwise it's basically a choice or personal preference.
Writing spells is tricky to describe in a short paragraph so for that I honestly do suggest you just study spell work for a while. After you get the feel of other spells already written, along with basic tools, herbs, moon phases, circles, etc...you'll have everything you need to write your own.
All good, hope this helps.