how do i divide and add column

i have a list with peoples id and date, the list say when a person Entered to website (his id and date). how can i show for all the dates how many people enter the site two days in a row?

the data ( 30,000 like this in diffrent dates)
01/03/2019  4616
01/03/2019  17584
01/03/2019  7812
01/03/2019  34
01/03/2019  12177
01/03/2019  7129
01/03/2019  11660
01/03/2019  2428
01/03/2019  17514
01/03/2019  10781
01/03/2019  7629
01/03/2019  11119

I succeeded to show the amount of pepole enter the site on the same day but i didnt succeeded to add a column that show the pepole that enter 2 days in row.

date    number_of_entrance
2019-03-01  7099
2019-03-02  7021
2019-03-03  7195
2019-03-04  7151
2019-03-05  7260
2019-03-06  7169
2019-03-07  7076
2019-03-08  7081
2019-03-09  6987
2019-03-10  7172

select date,count(*) as number_of_entrance
fROM [finalaa].[dbo].[Daily_Activity]
group by Date
order by date;

Answer

how can i show for all the dates how many people enter the site two days in a row?

I would just use lag():

select count(distinct person)
from (select t.*,
             lag(date) over (partition by person order by date) as prev_date
      from t
     ) t
where prev_date = dateadd(day, -1, date);

Your code suggests SQL Server, so I used the date functions in that database.

If you want this per date:

select date, count(distinct person)
from (select t.*,
             lag(date) over (partition by person order by date) as prev_date
      from t
     ) t
where prev_date = dateadd(day, -1, date)
group by date;