Transpose fixed number of rows to columns in SQL Server

Question

I'm facing an issue with the following problem.

A table I need to fill (let's say, Activities), has 3 columns (let's say Act1, Act2, Act3), where I need to place in order the last 3 activities the client has on that record.

I succeeded in creating the query that extracts the top 3 activities in decreasing order (this is a union of two different tables, as activities can be email or generic notes):

SELECT TOP 3 Concat(subject, ' | ', content, ' | ', creation) AS ActivityContent 
FROM   (SELECT TOP 3 'Email'             AS Tipo, 
                     a.regardingobjectid AS Regarding, 
                     a."subject"         AS "Subject", 
                     NULL                AS "Content", 
                     a.createdon         AS creation 
        FROM   mydb.dbo.activities a 
        WHERE  a.activitytypecode = 4202 
        UNION 
        SELECT TOP 3 'Note'        AS Tipo, 
                     ann.objectid  AS Regarding, 
                     ann."subject" AS "Subject", 
                     ann.notetext  AS "Content", 
                     ann.createdon AS creation 
        FROM   mydb.dbo.notes ann) AS Act 
ORDER  BY creation DESC 

This is the result of my query:

I now need to report the result ActivityContent of the 3 rows (these are ALWAYS 3, or maybe less if no activity has been done), to the Act1, Act2, Act3 columns.

+-----------------------------------------------+-----------------------------------------------+----------------------------+--+
|                     Col1                      |                     Col2                      |            Col3            |  |
+-----------------------------------------------+-----------------------------------------------+----------------------------+--+
| 'Test Nota' | 'Test Descrizione' | Oct 30 ... | 'Test Nota' | 'Test Descrizione' | Oct 30 ... | d |  | Oct 26 2018  9:23PM |  |
+-----------------------------------------------+-----------------------------------------------+----------------------------+--+

I'll say I'm not really familiar with SQL procedures in general, but I got lost within the tons of function I found online:

From what I understand, PIVOT could be one of the suitable functions, but it seems to be it has to be used when you need to aggregate (count, sum) within a column, and that's not my request.

I also checked APPLY, CROSS APPLY and so on, but I really didn't get the point on which has to be used, and how to implement it.

Thanks in advance for any hint.