Hey there! I'm happy to help!
To find the distance between points, you find the difference between the x values, square it, find the difference between the y values, square that, add the two numbers you got, and then square root it.
Find the difference between the x values.
-3-(-4)=-3+4=1
Square it.
1²=1
Find the difference between the y values.
3-3=0
Square it.
0²=0
We add the two numbers we got.
1+0=1
And we square root it.
√1=1
The distance between these points is 1.
Have a wonderful day! :D