If you are lucky, it's a baby manfrotto (728?), SLIK or Vanguard something similar... on a dslr it is only good for short lenses... sorry I know...
Course is a good idea... and the best course ever RTFM, so you know the jargon before you do the course...
ways to use a cheap tripod are:
Use as little height as possible... i.e. don't extend legs all the way
Delay timer, 2second mirror up...
Hang a bag of sand on it...
Starting to sound like audio... Manfrotto 055 is about the cheapest you can hang a 300mm lens off - not fully extended. Vangaurd tracker is a cheaper alternative, but save the schlepp of carrying it around and buy the 055...
From what I see you photograph... get a nice wide-ish angle prime. hell you'll probably get two for the price of the 75-300 IS, which is not bad, but not really a high quality lens either... 18-250mm is a JVC AVR, 75-300 is a Yamaha AVR, short primes from canon are either a EAR 5 watt SET/ 25W single class A... from Zeiss/Leica it'll be more like audionote / Firstwatt... Truthfully, you look like you want to take interesting photos, you'll get better results from short (in this case) primes