It sounds like your just starting off, so let me be the first to say welcome

.
First this first is that to do events, it helps to consult the manual (see the download section) to keep track of them all. Under the manual search for event in your index, it will bring up several selections. Read through them and pick which ones you want. In the example of event_impact the following example code is given in the manual to help you out. Simply take this code, put it in your .c file your working on, and include that .c file (assuming your working in lite-C/A7), then go into WED and under file you'll find map properties, in there include your file.
Re-load your map and insert a model, click on the model and you'll see all applicable actions under properties. Select the one you inputted the code in and it should work. There are plenty of walkthroughs that will help you do all of this in both the AUM's and other areas.
bounce_event is a function that is called each time an event is triggered, so anytime an event is triggered, it will go to here and pick from the applicable events you have defined (if available), in this case when your model hits something (another model for example) it will play a sound and remove itself from the game. The action itself is what is assigned to the model in question, the three lines turns on the event and attaches it to the model as a trigger-able event. The last line will tell what function to go to to search for the code to trigger.
Code:
function bounce_event()
{
if (event_type == EVENT_IMPACT)
{
ent_playsound(my,explode,50);
ent_remove(me); // disappear when hit
}
}
action exploding_barrel()
{
my.ENABLE_IMPACT = ON; // sensible for push collision
my.emask |= ENABLE_IMPACT;
my.event = bounce_event;
...
}
For more actions you'll have to be more specific to what your trying to do, and what your having problems with, no one is going to solve your complete problem just because you hit a road block, you have to go half way at the very least.
Your last question, I'm not sure what your asking, but you can make level blocks have different qualities based on there flags, just open one up and look at its properties, look in the manual for explanations.
Seriously though dude, make sure you read up on this stuff you will get horrible lost and frustrated if you just start doing stuff with no previous understanding.