I found solution, its working for me. when you are doing lookup use DE filed which is Mobilenumber field.

        %%[ 
        SET @idSubscriber = MOBILE_NUMBER 
        SET @rows = LookupOrderedRows("SMS_Journey_2_interest", 1, "MeetingDate Asc", "MobilePhone",@idSubscriber) 
        SET @RowCount = RowCount(@rows) 
        IF (Rowcount(@rows) > 0) THEN 
        VAR @ILRow, @name, @meetingtype 
        SET @ILRow = row(@rows,1) 
        SET @meetingDate = field(@ILRow,"MeetingDate")
        ENDIF 
        ]%%

        %%[ if @meetingdate > Now() then ]%%

        Hi %%=Field(@ILRow,"FirstName")=%%, we want to remind you about the upcomming 
        info meeting that you have with us next %%=Format(@meetingdate,"MM/dd/yyyy")=%% 
        at %%=Field(@ILRow,"MeetingPlaceAddress")=%% starting at %%=Field(@ILRow,"TimeFrom")=%%.
        If you can't make it please send us a What's up at:
        %%[ ENDIF ]%%

I found solution, its working for me. when you are doing lookup use DE filed which is Mobilenumber field.

%%[ 
 
SET @idSubscriber = MOBILE_NUMBER 
SET @rows = LookupOrderedRows("SMS_Journey_2_interest", 1, "MeetingDate Asc", "MobilePhone",@idSubscriber) 
SET @RowCount = RowCount(@rows) 
 
IF (Rowcount(@rows) > 0) THEN 
    VAR @ILRow, @name, @meetingtype 
    SET @ILRow = row(@rows,1) 
    SET @meetingDate = field(@ILRow,"MeetingDate")
ENDIF 
 
]%%

%%[ if @meetingdate > Now() then ]%%

    Hi %%=Field(@ILRow,"FirstName")=%%, we want to remind you about the upcoming 
    info meeting that you have with us next %%=Format(@meetingdate,"MM/dd/yyyy")=%% 
    at %%=Field(@ILRow,"MeetingPlaceAddress")=%% starting at %%=Field(@ILRow,"TimeFrom")=%%.
    If you can't make it please send us a What's up at:
 
%%[ ENDIF ]%%