"If you have a nursing friend, perhaps you can talk them into showing you how to start an IV. In my class, we practised on each other! It's really not hard to get the knack of it. If you have that skill, it is worthwhile to carry Ringer's lactate, and other IV administered fluids. In severe trauma/sickness simply getting a dextrose solution into the blood stream can be invaluable."
This is my point about having training. Just an ability to start an IV does not mean you know what to do with it. Thats why most EMTs can not start them, it takes more than to know how, you need the what and when and how much.
Case in point. RL aka Ringers lactate is NOT a dextrose solution, nor do you want to use a hypertonic glucose solution in a trauma case. Further most trauma is not treated with fluid challenge any more. It just blows the forming clots out.
First do no harm.
I would also strongly advise aganst ever using a tourniquet. In 20 something years of EMS I have never seen one used when it was needed or used correctly. Direct pressure, elevation and pressure points will do the trick. We dont even teach them anymore. In anything short of an amputation they are over kill and can kill someone who just needed basic care.
Get some real training and do only what you know or can be directed to do via radio.