All you need to make magic spells is knowledge on the topic itself and all that involves it . This also means not having unrealistic or ridiculousness notions on it.
When you say "All of those stuff" , are you perhaps referring to tools , materials and offerings?
For tools , most will tell you it is unnecessary as it is just something for you to channel your focus and aide your work.
For materials and offerings , it is entirely depends on what you are doing. If you are trying to appease an entity or being , an offering is always a viable option , though there are others. it depends on what you are trying to do .
I also don't think there is a need for you to prove to others that magick is true , I frankly do not see why one has the need to try such a thing and to me , it seems that the individual is pursuing the art for the most inappropriate reasons , doing it do to Wow , Inpress or whichever other reasons.