T-sql 2012 update foreign key value in primary table

In a special request run, I need to update locker and lock tables in a sql server 2012 database, I have the following 2 table definitiions:

CREATE TABLE [dbo].[Locker](
[lockerID] [int] IDENTITY(1,1) NOT NULL,
[schoolID] [int] NOT NULL,
[number] varchar NOT NULL,
[lockID] [int] NULL
CONSTRAINT [PK_Locker] PRIMARY KEY NONCLUSTERED
(
[lockerID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 97) ON [PRIMARY]
) ON [PRIMARY]

CREATE TABLE [dbo].[Lock](
[lockID] [int] IDENTITY(1,1) NOT NULL,
[schoolID] [int] NOT NULL,
[comboSeq] [tinyint] NOT NULL
CONSTRAINT [PK_Lock] PRIMARY KEY NONCLUSTERED
(
[lockID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 97) ON [PRIMARY]
) ON [PRIMARY]

GO

The locker table is the main table and the lock table is the secondary table. I need to add 500 new locker numbers that the user has given to me to place in the locker table and is uniquely defined by LockerID. I also need to add 500 new rows to the correspsonding lock table that is uniquely defined in the lock table and identified by the lockid.

Since lockid is a key value in the lock table and is uniquely defined in the locker table, I would like to know how to update the lock table with the 500 new rows. I would then like to take value of lockid (from lock table for the 500 new rows that were created) and uniquely place those 500 lockids uniquely into the 500 rows that were created for the lock table.

I have sql that looks like the following so far:

declare @SchoolID int = 999

insert into test.dbo.Locker ( [schoolID], [number])
select distinct LKR.schoolID, A.lockerNumber
FROM [InputTable] A
JOIN test.dbo.School SCH ON A.schoolnumber = SCH.type and A.schoolnumber = @SchoolNumber
JOIN test.dbo.Locker LKR ON SCH.schoolID = LKR.schoolID
AND A.lockerNumber not in (select number from test.dbo.Locker where schoolID = @SchoolID)
order by LKR.schoolID, A.lockerNumber

I am not certain how to complete the rest of the task of placing lockerid uniquely into lock and locker tables? Thus can you either modify the sql that I just listed above and/or
come up with some new sql that will show me how to accomplish my goal?

any relationship between the InputTable and the Lock ?

or any information from InputTable that will be insert into Lock table ?

There is a comboSeq in Lock Table. Where does this information comes from ?

thanks a lot!