My PhD programme is starting in less than one month but I don't feel ready for it. I had a brief discussion with my supervisor about the topic I will be studying. However, as it is a novel idea, I can't find many relevant papers. The things I learnt during my undergrad all appear to be too simple and useless for this topic. Postdocs in the lab don't know much about this topic either.

Has anyone had similar problem before? How did you get through it?   

Thank you so much everyone! I know what to do now. Wish you all a happy day!

I accepted a PhD offer two months ago but now I really want to go for another lab because I like the supervisor more. However I feel really bad for withdrawing the first offer -- will I make the the supervisor very annoyed? It is very possible that I may cooperate with him in the future. Should I just stay with the first lab as the two places are equally good (except one has the supervisor prefer)?

Hello! I've got a tricky choice and I will be so grateful if someone could give me some advice of what is the most important factor to consider. I got offer (and funding) from two quite equal labs. First lab has a clever supervisor and after the 40-minute talk I feel we will get along quite well. He gives freedom to PhDs and never push them. He is quite busy but is always available on phone/e-mail. But I have the fear that when I get stuck, I can't get out myself without much help. The second lab has a caring supervisor who spends lots of time with the students, but is less impressive than the first lab (less publications/awards). The second lab is geared towards translational drug discovery while the first lab is more theoretical/basic science. I want to try out translational research now and may want to pursue a career in industry after PhD. should I pick the second lab due to its connection with my future career?

Oh, and also, how bad is it to withdraw after e-mail acceptance of the offer 1.5 months ago? Will the supervisor get very annoyed?