[SalesForce] how to soql query on standard object product2

The product object is actually called 'Product2'.

From the documentation

Products are represented by Product2 objects. The Product object is no longer available.

Try changing your SOQL to something like below

list<Product2> products = [Select Id, Name From Product2];

You need to query by a particular id, or a list of ids, instead of all available ids. You can use a bind to provide an apex variable to a query for use in a filter.

From the Using Apex Variables in SOQL:

Account A = new Account(Name='xxx');
insert A;
Account B;

// A simple bind
B = [SELECT Id FROM Account WHERE Id = :A.Id];

You can also use a Id or a List<Id>.

List<Id> ids = new List<Id>(); // set from somewhere, or get from a list of sObjects
Id someId = 'a0Cc000000PAWBv'; // For example only, avoid hardcoding ids

List<Account> accounts = [SELECT ID, Name FROM Account WHERE Status = 'Active' AND Id IN :Ids];

Account account = [SELECT ID, Name FROM Account WHERE Status = 'Active' AND Id = :someId LIMIT 1];

This is a general example on how to use these variables in queries. Try to modify your code to use these, and either edit your question, or ask a new question if you encounter issues with your code.