I wish I could talk to you about more things, but I can't because my English isn't that good.
My English is still kind of poor, otherwise we could have much better conversations.
ーI wish I could talk to you about more things, but I can't because my English isn't that good.
「もっとあなたと話ができたらいいけど、私の英語はあまり上手じゃないので話せない」
I wish I could ... で「…できたらいいのに」
my English isn't that good で「私の英語はあまり上手じゃない」
ーMy English is still kind of poor, otherwise we could have much better conversations.
「私の英語はまだちょっと下手だから、そうじゃなければもっと上手く会話かできたのに」
my English is still kind of poor で「私の英語はまだちょっと下手です」
otherwise で「そうでなければ」
we could have ... で「私たちは…できたのに」
ご参考まで！
カナダ 
