The doctor advised to avoid unhealthy foods.

[Tait-ka]

Hi,

1.She requested to help her.
2.The doctor advised to avoid unhealthy foods.
3.The police ordered to open the door.
4.My mother forbade to go there.


Can I ask about whether the above sentences are correct? They are created by me.

 

[5jj]

None of them is correct. They all need a direct object after the verb, for example:

3. The police ordered the occupant to open the door.

 

[Tait-ka]

occpbant

Sorry. I could not find this word in any dictionary.

 

[jutfrank]

5jj meant to write 'occupant'. The typo has now been fixed.

 

[emsr2d2]

Hi.

Even a one-word sentence must end with a full stop.

1. space needed here She requested to help her.
2. space needed here The doctor advised to avoid unhealthy foods.
3. space needed here The police ordered to open the door.
4. space needed here My mother forbade to go there.

Always put a space after a full stop (unless it's being used as a decimal with numbers or part of an abbreviation.
As 5jj has explained, they're all wrong. The verbs you've used are all transitive so they need to be followed by a direct object. Have you studied transitive and intransitive verbs yet?
What prompted you to write these sentences? What grammatical point were you trying to practise?

Can I ask about whether the above sentences are correct?

See above. It's more natural to simply ask "Are the sentences above correct?"

They are were created by me.

See above.