It says

Bocchi za rokku Arigatou gozaimashita!

Bocchi za rokku is the name of the series (Bocchi the rock)

And the ri/i thing is just a handwriting thing. You can tell it's meant to be ri because the right side is much longer than left side

Edit: also, warra wouldn't be translated as laugh. The stem of verbs can't stand on their own. You will only see warau (laugh) as warai, waratte, warayou, etc., but never as just wara. It also wouldn't really make sense to make wara into warra. Some people will add the tsu to emphasize certain syllables, but in this case, it would just end up sounding weird and unnatural. And plus there's no real reason to emphasize syllables in this case

ぼっち　ざ　ろっく

ち　rather than ら And double consonant on rokku

Bocchi za rokku

Which apparently gets anglicized as Bocchi the Rock, the title of a manga.

Not sure what the deal is with あいがとう　instead of ありがとうthough. Unless it's a form of thank you I haven't encountered or just a typo.

It's り not い

Compare the lengths of the right-hand stroke between the り　in ありがとう and the い in ございました Edit: Another commenter already said much the same thing further down. My bad.