It's hard to say whether we are good friends or not, but I had a lot of fun!
It's hard to say whether we are good friends or not, but I had a lot of fun!
It's hard to say = 言いづらい（わからない）
whether or not = かどうか
we are good friends = 私達はいい友達（仲がいい）
but = でも・けど
have (a lot of) fun = （すごく）楽しむ
had＝haveの過去形
I had a lot of fun = すごく楽しかった
アメリカ合衆国 
