混んでるかもしれないから様子見で行こうっていう時は Let's go and check it out や Let's go and see what things are likeで大丈夫だと思います。Let's go and see if the shop is busy or not も大丈夫です。
Let's go and see if the shop is busy or not - 混んでいるかどうかを確認しにいきましょう
こんな風に使います
Aさん: There's a new bakery that opened up near my house recently. I heard it's really good.
Bさん: Oh really, it might be busy/crowded but let's go and check it out / It might be really busy but let's pop in for a look/ It might be really busy but let's go and see what things are like など
Pop in/into (somewhere) = visit briefly なので 様子見のニュアンスが十分含まれていると思います。