What you need to know
Two enemies : humidity and sudden changes in temperature.
First : do not leave the instrument in direct sunlight, in a car, or next to a heat source or radiator.
Second : do not forget to swab the instrument after use, so as to avoid an abnormally high level of humidity.
Lastly, common sense insists that you make sure the case is properly closed when carrying your instrument.
The art of assembling the instrument
It will be easier to put your clarinet together if you regularly grease the joint cork with cork grease.
The instrument is assembled by mounting the top joint on the bottom joint while holding the Bb correspondence key down. Make sure both joints are properly aligned.
Now simply add the barrel and the mouthpiece.
Wipe the instrument with a cloth after each use to eliminate traces of acidity resulting from perspiration on the hands. You must, however, be careful not to disturb the mechanism by pressing too hard.
The bottom of the screws also requires close attention as they are the ideal place for dust and grease to build up.
Of course, the inside of the instrument will be wiped by passing the swab from the bell towards the top by pulling gently on the piece of string. Make sure that the swab is always clean and that it does not leave any fluff inside the clarinet.