Easy Problem, But Need Help With Setting Up Database Keys.

I need help setting up my primary keys for a database table. Suppose I have two tables, as listed below. The first one is
a table of students and the course they are enrolled in. The second table is a table of test scores. Never mind that this
could be designed better. Please just using my design as an example, I need help.

 

 

First table - Student Table

Student Id    Student   Course   Building
1                   Joe       Math101     Primus Hall
2                   Jake      Engl103     Indigo Hall
3                   Mary      Art107       Money Hall

So my question is the following. On my second table below, can I just have
one Key as the Primary key? Just like in the first table. I will have a
primary key named "TestId"

If so, how do I set up my table so that the values in the "TestId"
table will be automatically generated upon inserting into the Test
score table.

 

Second table - Tests Score Table:

TestId    StudentId TestScore  Date
  1           1         99         9/1/07
  2           1         100        9/15/07
  3           1         88         9/16/07
  4           2         99         9/1/07
  5           2         100        9/15/07
  6           2         88         9/16/07
  7           3         79         9/1/07
  8           3         100        9/15/07
  9           3         100        9/16/07