As the temperature rise outside we need to be aware of where are leaving our instruments. They are sensitive to heat. Car interiors are the biggest offenders. So what can happen? I have learned most of these from personal experience, thankfully most of them years ago.
Rosin
It melts. It will harden again and still be usable, but the resulting shape may be very odd. This is a before and after of rosin left out on a day no hotter than 80 degrees. Imagine a hotter day and/or in a car.
Your Instrument
What is the solution? Plan ahead. Stop by home to get the instrument when you need it, take it into work, or take it with you when you get out of the car. My instrument comes into the store often. Just a get a shopping cart and push it through the store. It looks funny, but your investment is safe.
For some students they find it hard to remember the bow direction at first. Which way is up? Which way is down? Where do I start? This picture might be helpful. Maybe post near where you practice.
Learning key signatures, except F and C, involves two rules. There is one rule for sharps and one for flats. This is detailed i this document.
Remembering the order of flats and sharps. There are seven to remember, which might see like a lot, but the order is just reversed. So, if you know the first four flats (BEAD) and the first three sharps (FCG) you can put either list together. Remember that they always appear in this order and the precending sharps, or flats, are always there. In other words, you will never wee a G# in a key signature alone. F# and C# will proceed it. This might help see the relationship.
There are two key signature that you can not use a rule to name. Those are F and C. These fluffy(F) cats(C) can help remember these key signatues.
This gives a short desccription of each of the eras in music.
Reserved for the future.