The answers are in the end👇
Particles are one of the most confusing aspects for the Japanese learners.
Here, you can learn three types of 「を」.
・BBQをします (I do BBQ)
・ジュースを飲（の）みます (I drink juice)
・日本語（にほんご）を勉強（べんきょう）します (I study Japanese)
・映画（えいが）を見（み）ます (I watch movie)
・音楽（おんがく）を聞（き）きます (I listen to music)
「を」 used in the sentences above all indicate [Object].
The object is the noun which receives the action of the verb.
Although you may not have thought about it, English also has a direct object.
In English, the direct object usually comes right after the verb.
In order to know a noun is an object, Japanese uses object marker 「を」,
English, on the other hand, uses word order.
When you say 「橋を渡ります」, the bridge is not the place where you want to go.
Because the place you want to go is over the bridge, you need to across the bridge.
Here also we use 「を」 as its particle.
Let’s take a look at other examples.
・信号（しんごう）を右（みぎ）に曲（ま）がります (I turn the signal to the right)
・階段（かいだん）を上（のぼ）ります (I climb the stairs)
・この道（みち）をまっすぐ行（い）きます (I go straight on this road)
・楽（たの）しい時間（じかん）を過（す）ごします (I spend a pleasant time)
・飛行機（ひこうき）が空（そら）を飛（と）びます (An airplane flies in the sky)
From these sentences, you can understand the nouns showed right before 「を」
are not the place where Subject wants to go.
Those are [passing point].
This concept is similar to the use of ②
・電車（でんしゃ）を降（お）ります (I get off the train)
・大学（だいがく）を卒業（そつぎょう）します (I graduate from the collage)
・家（いえ）を出（で）ます (I leave the house)
・会社（かいしゃ）を辞（や）めます (I quit the company)
・病院（びょういん）を退院（たいいん）します (I will be discharged from the hospital)
The places that each noun shows are where you currently are.
You are going to make some actions from there.
You are on the train, and you are going to get off the train→電車を降ります
You are in the collage, you are going to graduate from the collage→大学を卒業します
This type of 「を」 marks [starting point].