Hi,I'm from Japan.
Firstly, maybe you heard that"いいえ、アメリカのえいがをよくみます。",not "えいがよくをみます”.
you can't put these adverbs before postpositional particles like "を","は”.
These adverbs are used a lot of ways.
If sentences are written "私はよく喫茶店に行きます。",it emphasize "喫茶店" and mean that I often go to "coffee shop" ,but I don't talk about other shop.
If sentences are written "私は喫茶店によく行きます。" , it emphasize "行く" .
But Japanese also say "よく私は喫茶店に行きます。" and it emphasize "I" and mean that I don't talk about other people,but "I" often go to coffee shop.
Japanese put these adverbs at various part of sentences but usually put before noun or verb.