I think your questions are too broad to answer in detail. The easiest way to answer all of those questions is probably to examine the Hoth siege .map which is included in the Raven map SDK. Mapping in Siege basically requires a combination of using entities in your map (like triggers and info_siege_objectives) and editing text files in the .pk3 (like the .siege and .team files).
In short/generic terms though:
Fenix wrote:wanna make a point where offense have to reach to complete the first objective
yews a trigger_once brush which targets an info_siege_objective
Fenix wrote:how do you change the spawn position
yews the "startoff" key on your info_player_siegeteam1 and info_player_siegeteam2 and target those entities to turn them on and off.
Fenix wrote:how do you print off message
yews a target_print entity.
Fenix wrote:give points to the player
This is not something you map, it's coded into the game.
Fenix wrote:how do you make something carriable
yews a misc_siege_item entity and set the "goaltarget" key to the delivery spot trigger
Fenix wrote:how to do siege classes.
Look at the .team and .siege files in a Siege map with custom classes (like Cargo for example).
Fenix wrote:How to make consoles that people can hack
Create a console in the map and place a trigger_once or trigger_multiple brush in front of it. Set the "usetime" key to number of milliseconds you want it to be hacked. Also set the "idealclass" key to only allow a specific class to trigger it (i.e. "Rebel jan").