「これから始めるならこれを買っておけば間違いないと思います」はIf you are just starting out,you can't go wrong with buying this oneでしょうか？「何を買おうか迷ったらこれ一択です！」ならIf you are not sure what to buy,this is the one you should choose!で合ってますか？
If you don't know what to buy, this is the one for you. You can't go wrong with it.
こんにちは！
ご質問ありがとうございます。
ご質問にある表現で言いたいことは伝えられます。
If you don't know what to buy, this is the one for you. You can't go wrong with it.
とすると、『何を買っていいのかわからない場合は、こちら。これを買っておけば[間違いない](https://eikaiwa.dmm.com/uknow/questions/110385/)と思います。』と言えますね！
参考になれば幸いです。
If you are just starting out, you can't go wrong buying this.
If you can't decide what you should buy, I would highly recommend this.
この場合、次のような言い方ができますよ。
ーIf you are just starting out, you can't go wrong buying this.
「これから始めるなら、これを買えば間違いないよ」
ーIf you can't decide what you should buy, I would highly recommend this.
「何を買うか迷ったら、これがすごくおすすめです」
ご参考まで！
日本 
カナダ 
