If lucky, based on previous personal experience, you should be able to start to cycle with low resistance in 4-6 weeks IF they have to do nothing else than trim the meniscus and you get your range of motion back quickly. If they try to stitch the meniscus, have to try to patch up cartilage holes with microfracture, etc then likely much longer. Indeed, you may be on crutches for a number of weeks. A meniscus repair can be 6 weeks non weight bearing (although this is unlikely if you’re over 30ish as the menisus is likely degenerate and non stitchable).
Problem is, even with MRI, they can never be sure what they’ll find and therefore what they’ll do!
Not all meniscus tears need surgery, if no major swelling, locking, giving way and as removing meniscus increases the development of arthritis (plus the risks of surgery), it can be best to leave well alone and get good physio if pain the only symptom