The Winter Soldier, also known as Bucky Barnes, is depicted as being highly trained in various forms of hand-to-hand combat and martial arts. However, there is no specific number mentioned in the Marvel Cinematic Universe as to how many martial arts he knows.

He is not specifically depicted as using karate in the Marvel Cinematic Universe. However, as a highly trained assassin, he is likely proficient in a variety of martial arts styles, including close-quarters combat techniques.

It is possible that the Winter Soldier may have been trained in Taekwondo or a similar martial art that utilizes kicks, as he is depicted as highly skilled in hand-to-hand combat. However, this has not been explicitly stated in the Marvel Cinematic Universe.

He is considered one of the most formidable and skilled assassins in the Marvel Cinematic Universe, capable of taking on multiple opponents at once and holding his own against some of the strongest characters in the franchise. His combat skills, combined with his physical strength and agility, make him a formidable opponent in any fight.

The Winter Soldier is depicted as being physically strong and highly skilled in combat, but it is not stated that he is stronger than Captain America. While both characters are depicted as highly capable warriors, Captain America is considered to be one of the strongest characters in the Marvel Cinematic Universe due to his enhanced physical abilities as a result of the Super Soldier serum.

In terms of raw strength, Captain America is typically portrayed as being stronger than the Winter Soldier, although the Winter Soldier's combat skills and agility can still make him a formidable opponent.