Oh wow, I wasn't expecting such an in-depth reply. Thanks a lot! I went and watched some videos of more experienced players and I noticed the guy jungling (dunno if I'm using it correctly; he was sending his spiderlings to go fight the boss-like mobs?) with his spiderlings. Is there a way to select all your spiders but not yourself? I did shift + drag but sometimes the corner of the selection will grab me too.
Yeah you want to send the spiders to farm the jungle while you stay in the lane. It's very risky to go into your opponents jungle yourself, so it's best to stay with your webs in the lane. There is a key for "select all non-hero units i control" which you can change to whatever you want. Mine is set to the tilde (~) key, but I don't remember if that is the default. You can change all your keybinds in the game options.
Since you are apparently even newer than i thought, if you haven't done it already you should really change your hotkeys to be something comfortable. I think the default item use hotkeys are the keypad numbers, which is obviously terrible. I wound up setting items to F1/F2/Z/X/C/Space with D and F set to skill 1 and skill 2 (used for characters that can gain extra skills such as Invoker, Rubick, and Lone Druid). I use 1 for select hero and 2,3,4 etc for hotkey groups for use with Chen and Bestmaster. This all made sense to me since I came from an SC2 background, but you can set to whatever feels most comfortable. I know some people will even just change their hotkeys depending on what hero they are.
Oh and you need to set hotkeys for selecting the courier and bringing up the shop. I use the side mouse buttons for that but you can easily set them to keyboard binds as well.
Also if you want to play let me know, my name in dota is Winterminute. I've been playing guild wars 2 recently but I still play a fair bit of dota, so hit me up if you see me on!