Mac air keyboard and system glitch

Mac air keyboard glitches : keyboard always on Caps even symbols (can’t type password, etc.) Mac air “system” glitch : when I go to Safari, it glitches and every time I click on something, it bookmarks it, so I have to go to the reading and open the website from there but it glitches a lot (stripes on screen and stuff) please help me. I haven’t used since it crashed (haven’t used it in 3 months) which is horrible.