Give us some more background here. How did you come to be in this position of studying abroad with coursework recommended for N1-level students, having only been studying the language for a month?
The reality of the situation is that you won’t be N2 or N1 by April. I think to set that as an objective is just going to be a burn out on study hours and a feeling of failure. I’d agree with @erie-canary in that N4 is probably doable, N3 maybe if you really get after it and have a natural knack for it. A lot depends on your ability, potential study hours, self discipline, etc. You’ll get where you’ll get to. Do your best, a little better every day and feel good about it.
To be honest I’d get in touch with whoever is putting this whole thing together, explain your situation, see what they say. Maybe they have some suggestions, or can change some coursework around or something.
With regard to books - “Should I do Genki? Or Minna no Nihongo?” Realistically I’d plan on having a variety of resources, especially if you want to absorb as much as possible. Probably several textbooks, grammar dictionary, study materials, maybe some paid tutoring on iTalki, something like that. In the grand scheme of things, Genki 1 is just one tiny step to proficiency.
Two things I’d definitely focus on that can be easy to skimp on when self-studying:
- Listening practice
- Active use of the language
When I was in Japan recently, listening was by far the most challenging thing. People will generally either speak to you in English, or full speed native Japanese. A shadowing book may be a good place to start. Has native Japanese audio, Japanese transcription, English translation.
With regard to active use… we often talk about JLPT levels, but they’re purely for recognition and not for writing or speaking ability. Something like BunPro, or HelloTalk, or iTalki sessions, will get your brain actively recalling grammar and vocabulary.