This question already has an answer here:
I've been looking for an software engineering internship for the end of my studies. I was accepted at company X. However, a colleague from my previous job proposed me another job at company Y.
While company X looks like a very good job, company Y has great potential so I'd like to have an interview with company Y and make my choice after. Company Y makes video games and that excites me a lot but I didn't have a look at it from the inside as I did for company X. Y is potential for an awesome working experience while X is security (and also a great company). If I was forced to make a choice now, I'd take company X.
Another problem is that the recruiting process is not really started with company Y. I have a contact telling me "I'm good" and I sent my CV but that's all.
However, company X wants me to come sign the contract this week. The job will only start in 3 months. Should I tell them to report my appointment in, let's say, 2 weeks? Should I go at the appointment and explain them that since I want to stay open-minded, I prefer finishing my other interviews before signing anything? Should I say nothing, sign the contract and then cancel if I decide to join company Y?