How to do some basic thing?

I’m a total noob at doing all HL2 tricks. I watched the speedrun video and was amazed by how fast you could bunnyhop and how you could just grab an item off of the ground and fly on it like nothing. I was just posting on here to maybe find out how to do these things? I’ve tried figuring them out myself, but to no avail. Anyone mind explaining how to do these 2 things?

read the tricks.txt which come with all versions when you dl with torrent, can probbably find it somewhere else on this forum are explanations how to do all tricks of HL2DQ