This is one of the questions I hear most often. And it's one of the hardest to answer. I like to start my answer with another question: What does "conversational" mean?
When you walk out the door at the beginning of the day, or when you start a Zoom meeting with a colleague, you don't have a script in front of you with the words you will need. If you bump into someone at the supermarket, you have no idea what he/she might talk to you about. Because speech is completely improvised, there is no way to predict what conversations will be about. So, for me, "conversational" means "able to talk about a lot of things".
Learning a language is a commitment, just like learning an instrument. And it should be as enjoyable as learning an instrument. If you started to play the guitar and asked your teacher, "How long before I can play in a band?" the answer would depend on a lot of things. In the same way, the time it will take to become conversational will depend on your commitment to developing your vocabulary, grammar, and listening skills. Just knowing how to say a bunch of phrases isn't enough.
I encourage my students to, instead of making a deadline, or giving yourself a time frame, make a commitment. Learning a new language is a life-long endeavor. And let's be honest, if you don't love it, you probably won't stick with it. But if you do make a commitment and stick with it, a new language will open your world to new understanding, new relationships, and new experiences. It has changed my life and it can change yours.