Posting some videos with last hitting advice or explaining it in more detail would actually be useful.
You can see from the dotabuff game he is very inexperienced (not critising btw) we have all been there. He stills has a GG branch, tango and salve by the end of the game, has one big item completed plus a wraith band.
There is a bunch of stuff you need to learn about lane control/last hitting/item progression etc but it's most likely too much info to take in all at once. Also look at his team, that's pretty much 5 carrys right there, wouldn't surprise me if they had no courier for the first 10 minutes of the game.
No offense taken, Im a noob and I know it

I normally follow one of the in-game builds with regard to buying items but sometimes I seem to get it into my head that I need to get that shiney item and seem to ignore the mid game items

Cheers