painting a painting
The Spanish phrase 'pintar un cuadro' translates to 'painting a painting' in English. It's often used to refer to the act of creating an artistic work on a canvas or similar surface using paint. An individual who 'pinta un cuadro' is someone who is creating, or has created, a painting.
I would like to paint a picture on our summer vacation
This sentence is expressing a desire to perform the act of painting a picture during a trip (vacation). The use of 'Me gustaría' indicates the conditional 'I would like', followed by the infinitive verb 'pintar'.
She decided to paint a picture as a gift for her grandmother
This phrase is telling us that a girl made a decision to paint a picture with the purpose of gifting it to her grandmother. In this sentence, 'decidió' is the preterite tense of the verb 'decidir' which means to decide.
I can paint a picture of the scene if you have a little time
The speaker in this sentence is suggesting that they can paint a picture depicting a certain scene if the listener can spare a little time. Here, 'Puedo' is the first person singular form of the verb ‘poder’ which translates to 'can' in English.