I'm thinking about leaving after 6 months as a PhD student
I just read your question and I decided to sign up here so that I can answer your question.
As you say PhD is a long &quot;journey&quot;, you are going to spend several years working on that project, and I really think that you should &quot;believe in&quot; your project to keep motivated. If it helps, I'm in my 3rd year of PhD, I am studing microbial ecology, which is not exactly my field (I studied Biotechnology and little ecology), but I was interested in the field I could see why it was important. Although I don't see future applications in industry (at least right now), I am aware of the importance of doing &quot;basic research&quot; and builging a general knowledge that help to better understand the world...
During my 2 and a half years I have had good and bad moments, and sometimes, talking with my supervisors helped (I must day that I'm very lucky because they are great persons), but most of the time, motivation depended on me, on seeing through the &quot;bad days&quot; and working on mental health, which includes not working on the week-ends, spending time out of the office, doing sport, talking about my work-related problems with other people in and outside academia, taking holidays...
This is my experience, if you have just started and you already have this feeling, I think you should look for other project or other type of job. Sometimes, deep inside, you know what you want but you are a bit scared/worried/embarrased to confront it (I don't want to make any assumptions). Problems with invoices, books, money etc are usual in all labs (in my experience), so you might encounter similar problems if you move to other lab. But mental health is so important!! If talking to your supervisor doesn't help, try other people around in the lab, with the experience of doing a PhD. You should be the most motivated person about your project, if you cannot see its usefulness, or you don't like it, it will get worse... In the next years, you will need to defend your project in papers and dissertations, you will have to read a lot of literature related to that to build a good knowledge, so at least you should enjoy reading and learning about that topic, if not, everyday will be a torture...
In any case, don't feel bad about your supervisor if you finally decide to leave, I know it can be embarrasing after the month he/she has spent teaching you etc, but if you think it is the right decision, you will be grateful in the future ;)
Hope this helps!