Necesitamos ayuda profesional.

Necesitamos is the present tense form of necesitar for nosotros/nosotras (we).

So:

• necesitar = to need
• necesitamos = we need

The ending -amos tells you the subject is we.

In Spanish, the subject pronoun is often left out because the verb ending already shows who is doing the action.

So both are possible:

• Necesitamos ayuda profesional.
• Nosotros necesitamos ayuda profesional.

The version without nosotros is more natural in most situations. Adding nosotros usually gives extra emphasis or contrast, such as:

• Ellos no quieren llamar, pero nosotros necesitamos ayuda profesional.

Because ayuda here is being used in a general, uncountable way, like help in English.

Spanish often leaves out the indefinite article with general things you need or want:

• Necesitamos ayuda.
• Necesito agua.
• Buscan trabajo.

So Necesitamos ayuda profesional sounds natural.

If you said una ayuda profesional, it would usually sound more like a specific kind of aid/help rather than the general idea of professional help.

Because ayuda here means help in a general sense, and that is usually singular in Spanish.

• ayuda = help
• ayudas = aids, forms of assistance, support measures, grants

So:

• Necesitamos ayuda profesional = natural
• Necesitamos ayudas profesionales = sounds like several types of professional assistance or support programmes

In Spanish, most adjectives normally come after the noun.

So:

• ayuda profesional = professional help

This is the standard word order. Putting the adjective before the noun is much less common here and would sound unusual.

Yes. Profesional does agree with ayuda, but adjectives ending in -al do not change for masculine vs feminine in the singular.

So:

• ayuda profesional = feminine singular
• trabajo profesional = masculine singular

The form stays profesional in both cases.

It only changes in the plural:

• ayudas profesionales
• trabajos profesionales

Here it is an adjective describing ayuda.

• ayuda profesional = professional help

But profesional can also be a noun:

• Es un profesional. = He is a professional.

So the word itself can do both jobs, but in this sentence it is clearly an adjective.

Usually, yes, or at least professional/expert help.

It suggests help that comes from someone qualified, trained, or acting in a professional capacity.

A very close alternative is:

• Necesitamos ayuda de un profesional.

That version makes the idea of from a professional person more explicit.
Ayuda profesional is a little more compact and very natural.

A simple guide is:

neh-theh-see-TA-mos ah-YOO-da პრო-feh-syo-NAL

More accurately in most of Spain:

[ne.θe.siˈta.mos aˈʝu.ða pɾo.fe.sjoˈnal]

A few useful pronunciation points:

• The c in necesitamos is before e, so in most of Spain it sounds like th in Castilian Spanish.
• The stress is on:
  • ta in necesitamos
  • yu in ayuda
  • nal in profesional

Yes. The rest of the sentence can stay the same; only the verb changes to match the subject.

For example:

• Necesito ayuda profesional. = I need professional help.
• Necesitas ayuda profesional. = You need professional help.
• Necesitan ayuda profesional. = They/You all need professional help.

So necesitamos is specifically the we form.