Мы решили совершить поездку утром.

Because after решить meaning to decide, Russian usually uses an infinitive to say what was decided.

So the pattern is:

• решить + infinitive

Examples:

• Мы решили поехать. = We decided to go.
• Я решил позвонить. = I decided to call.
• Они решили остаться. = They decided to stay.

In your sentence, совершить is the action that was decided on.

Совершить is the perfective form, while совершать is imperfective.

Here, perfective makes sense because the sentence is about deciding to do one complete trip as a single event.

• совершить поездку = to make/take a trip, seen as a whole completed action
• совершать поездки = to make trips, often repeatedly or as a process/habit

So:

• Мы решили совершить поездку утром. = We decided to take a trip in the morning.
• Мы часто совершаем поездки утром. = We often make trips in the morning.

Because it is the direct object of совершить, so it is in the accusative case.

The base form is:

• поездка = trip

Since поездка is a feminine noun ending in -а, its accusative singular changes to -у:

• nominative: поездка
• accusative: поездку

So:

• совершить поездку = to take/make a trip

Yes, it is natural, but it sounds a bit formal or bookish.

Совершить поездку is a standard collocation meaning something like:

• to make a trip
• to take a trip
• sometimes to undertake a trip

In everyday spoken Russian, people often use simpler verbs instead, for example:

• Мы решили поехать утром. = We decided to go in the morning.
• Мы решили съездить утром. = We decided to go and come back / make a trip in the morning.

So совершить поездку is correct, but slightly more formal than casual conversation.

In this sentence, мы is helpful because the past tense form решили does not show person clearly.

In Russian past tense:

• решил = masculine singular
• решила = feminine singular
• решило = neuter singular
• решили = plural

But решили could mean:

• we decided
• you (plural/formal) decided
• they decided

So if you remove мы, the subject becomes unclear unless the context already tells you.

That is why Мы решили... is very natural here.

Утром is the instrumental singular form of утро and is used adverbially to mean in the morning.

This is a common Russian time expression:

• утром = in the morning
• днём = in the daytime / during the day
• вечером = in the evening
• ночью = at night

So unlike English, Russian often does not need a preposition here.

Compare:

• утро = morning
• утром = in the morning

In this sentence, the most natural reading is that the trip is planned for the morning.

So:

• Мы решили совершить поездку утром.
  most naturally = We decided to take the trip in the morning.

If you want to emphasize that the decision itself was made in the morning, Russian more often changes the word order, for example:

• Утром мы решили совершить поездку. = In the morning, we decided to take a trip.
• Мы утром решили совершить поездку. = We decided in the morning to take a trip.

So word placement helps show what утром is modifying.

Yes, absolutely. That version is often more conversational.

Difference in feel:

• Мы решили совершить поездку утром.
  more formal; focuses on the trip as an event

• Мы решили поехать утром.
  simpler, more everyday; focuses on going

Which one sounds better depends on context. If you are just talking naturally, поехать is often more likely. If the style is formal or written, совершить поездку fits well.

Решить and решиться are related but not the same.

• решить = to decide
• решиться на что-то / решиться сделать что-то = to make up one’s mind, to bring oneself to do something, often after hesitation

So:

• Мы решили совершить поездку. = We decided to take a trip.
• Мы решились совершить поездку. = We finally brought ourselves to take the trip / We dared to take the trip.

The reflexive form usually suggests hesitation, difficulty, or emotional effort. In your sentence, plain решили is the neutral choice.

Yes. Russian word order is flexible, but different orders can change focus or emphasis.

For example:

• Мы решили совершить поездку утром.
  neutral; focus often falls naturally on утром

• Утром мы решили совершить поездку.
  emphasizes in the morning as the time of deciding

• Поездку мы решили совершить утром.
  emphasizes the trip itself, perhaps contrasting it with something else

So the grammar stays correct, but the communicative focus changes.

Not exactly.

• поездка usually means a trip, often something fairly concrete and bounded
• путешествие is more like a journey or travel, often sounding broader, longer, or more adventurous

So:

• совершить поездку = take a trip
• совершить путешествие = undertake a journey

In your sentence, поездка is the more ordinary and natural choice for a normal trip.

Because Russian has no articles like a, an, or the.

So поездку can mean:

• a trip
• the trip

Context tells you which is meant.

In this sentence, English would usually say a trip, but Russian simply uses the noun without any article word.