I am a student employee who applied for frontend development and have no experience the specific programming language nor framework. My employer, not familiar with what I exactly have to do, wants me to build a simple website (but full stack) as the first task within 2-3 weeks with 15h per week. I have a strong gut feeling that I won't make it in time and would like to tell him as soon as possible. How?
I am a student employee and will start working in IT by next week. In my job interview we worked out what I am capable of and I said that, as stated in my application letter, I want to do frontend development. They convinced me of also handling a bit of DevOps (deployment of the server, installing and updating needed packages). I have 1 year of web development experience in Django (university projects). Since I have done DevOps with the latter in the past I thought I could handle it. My future boss also asked me how long it would take me to complete the task of making a website in their desired language and framework, which I am not familiar with.
I replied that I didn't have the appropriate experience and could only guess out of the blue. After he (has never done any programming) said it should be probably done between 2 to 6 weeks I said maybe 4 weeks could be a robust estimate.
At the end of my interview he stated that my boss' boss asks for that website on a daily basis and we should be able to show the "website without being ashamed of it" in 2.5 weeks.
A couple of hours I had a few doubts. What I actually have to do is: learn the language (PHP), learn WordPress, deploy and install WordPress and then "create" the website. By that I mean find a fitting theme for the already existing design of the company's design team or build a custom theme together with their design team. Even though it is a simple website and no webapp and the fact that they already have their design set I have a strong feeling that the deadline in 2.5 weeks is too tight.
How can I smoothly convince my boss that his estimates are a bit too ambitious?
Especially because currently I am working "in advance", meaning that I have not signed a contract, yet. Also I feel that even 4 weeks à 15 hours, so 60 hours are not enough for me adapting to a whole new language, whole framework and doing full stack development plus some extras regarding security and scalability.
Additional info: The company does not have another frontend developer, I am on my own for the whole part. I get along really well with the design team and the boss, so I have the feeling that I can speak honestly about my doubts.