Anyone with experiece of getting their parents to come to Portugal.

For non UK/EU citizens is something like that:

During the first three months of their stay in Portugal, your parents who do not have EU citizenship are not required to apply for a residence card in order to live with you.

After spending 3 months in Portugal, non-EU family members have 30 days in which to apply for the residence card (Cartão de Residência) certifying their right to live in Portugal.

To apply for a residence card:
- They will need a valid passport
- Your certificate of registration as a EU citizen or other proof that you reside in Portugal
- A proof of family tie (e.g. birth certificate)
- A proof that they are in your charge


But for UK citizens the rules are different for at least 31 December 2020.
On 1 January 2021, the rules for EU citizens living in or moving to the UK will change. The same applies to UK nationals living in or moving to an EU country.

Please read this in english, and Brexit section in particular:

europa.eu/youreurope/citizens/residence/documents-formalities/non-eu-family-members-residence-card/portugal/index_en.htm

Hello, what a proof that they are in  my charge could be? Plus, how will they come to portugal at first? Is it through a tourist visa?

Hello, what a proof that they are in my charge could be? Plus, how will they come to portugal at first? Is it through a tourist visa?
-@Dany Baydoun

It depends on where the Non EU citizens come from as there are different rules for different countries.

@DrHaq Did you have a look at the SEF website? The Immigration section should provide a lot of information regarding the immigration based on family reunification. Once you went through this information, questions might still exist which members of this forum can possibly answer.