Possible but costs a lot: Enter into google "fahrschule motorrad mieten site:.ch" (w/o the quotes )
Normally cheaper to buy a banger and sell it after you did the courses and exam (or keep if you like it). Be aware the you might drop the bike while practice the maneuvers or otherwise. Even a small scratch can eat up all of your deducible which is CHF 500 to 1000.
I said normally as it look like the used motorcycle market is tried up. All others had the same idea, or those which have a bike do not want a new one. There is also the issue that there are not that many new bikes on the marked as well.
If you are 25 years or older, and you want to start the process this year go for the full A unrestricted license. There is no difference in the process except that the vehicle for the exam needs at least 35 kW (35 kW exactly is good enough if you get your learners permit this year).
For official learning materials for theory exam see:
Theory exam can be don in English in some cantons.
The mandatory driving lessons are covered bz the basic motorcycle training (Grundkurs). Search in Google for "Grundkurs Englisch".
As you do not have any license you would also have to do the mandatory traffic safety course (Verkehrskunde VKU). If you apply for the learners permit before 2021 you will to this after you passed the theory exam. If you apply for a learners permit 2021 or later you must do it before the theory exam.
compared to B it is a headache indeed as you need your gear, namely bike and armor, depending on school the requirements vary - some refuse jeans, others require only motogloves and a helmet. So you might already start looking for protective gear, either used on FB marketplace, Tutti, or new in an outlet.
even for basics like clutch control you have to have a learners license, aka Lernfahrausweis, but if you have a buddy with a bike...
if you manage to get the Lernfahrausweis this year, you'll have 4 months in 2021 to the Grundkurs done, this lifts off some pressure to manage everything this year. But then we don't know what 2021 wil bring. However, due to Corona this year Kanton Zürich extended learners' permits by two months, otherwise they don't have any mercy when it comes to expirations.