First Anime

Oh boy, where do i start xD. I do not know what you may like so i will just list the ones i like so there will be variety to choose from:
Sword Art Online - Obviously
My Hero Academia
RWBY - American anime, quality gets better with each season
Miss Kobayashi Dragon Maid - Chill little comedy romance
That time i got reincarnated as a slime - Overpowered MC that can do everything, my current fav
Hunter X Hunter - Many episodes, catchy story and lovable characters, OP fights
The Saga of Tanya the Evil - Evil MC, set in the Empire (Germany), world war type thing, isekai (mc gets send to a different world)

Tanaka kun is always listless - Hidden gem, i would check this one first if you don't like it check the others. It's a slice of life anime around the relationship of the 2 best friends and the people around them.