Can you please give me some tips about some problems I have in skateboarding?

Hi! I’m just new to skateboarding… I actually found skateboarding a bit easy at first until I found out how to stop the skateboard properly and also, I want to know how to sustain a manual (or if you have an easier or a better trick for someone new to skateboarding) since my reflexes tend to stop me from doing these things… So please give me some tips on how to do these things properly!

Here are videos on most of the core skateboarding tricks.

http://www.skateboardingdictionary.com/How_to_Ollie.html