How does a integer data record store in SQL Server page
One important thing to keep in mind is that rowstore tables have a minimum row size of 9 bytes. You can see some details about that in the answer and comments here. If you're going to be creating sample data and digging around in pages I recommend creating at least a few columns to make what you're looking at more clear. Otherwise you can run into a case where a table with a single TINYINT column appears to take up as much space as a table with a single SMALLINT, which doesn't make sense at first.

CREATE TABLE dbo.X_TINYINT (ID SMALLINT NOT NULL);
CREATE TABLE dbo.X_SMALLINT (ID SMALLINT NOT NULL);

INSERT INTO dbo.X_TINYINT WITH (TABLOCK)
SELECT TOP (100000) 0
FROM master..spt_values t1
CROSS JOIN master..spt_values t2
OPTION (MAXDOP 1);

INSERT INTO dbo.X_SMALLINT WITH (TABLOCK)
SELECT * FROM dbo.X_TINYINT;

sp_spaceused 'X_TINYINT'; -- 1096 KB reserved

sp_spaceused 'X_SMALLINT'; -- 1096 KB reserved