1.Are there any points in the game, before the end when you know who the winner is going to be? How do you know?
If you are on the counter 7, 5, 3, 2, 1 you can win the game if you are on 7 take 1 so you get 6 the other person will take 2 or 1 so then you can just take 1 or 2 so you can take the counters down to 3 so that means you will win because if they take 1 you just take 2 is they take 2 you just take 1 then you win!
2.Can you find a way to play so that you are sure you will win right from the start?
Here is a tip for winning but it depends on what nim you are playing:
Nim-7
1 counter take 1
2 counters take 2
3 counters take 1 or 2
4 counters take 1
5 counters take 2
6 counters take 1 or 2
7 counters take 1
Nim-9
1 counter take 1
2 counters take 2
3 counters take 1 or 2
4 counters take 1
5 counters take 2
6 counters take 1 or 2
7 counters take 1
8 counters take 2
9 counters take 1 or 2
Nim-11
1 counter take 1
2 counters take 2
3 counters take 1 or 2
4 counters take 1
5 counters take 2
6 counters take 1 or 2
7 counters take 1
8 counters take 2
9 counters take 1 or 2
10 counters take 1
11 counters take 2
Nim-13
1 counter take 1
2 counters take 2
3 counters take 1 or 2
4 counters take 1
5 counters take 2
6 counters take 1 or 2
7 counters take 1
8 counters take 2
9 counters take 1 or 2
10 counters take 1
11 counters take 2
12 counters take 1 or 2
13 counters take 1
Nim-15
1 counter take 1
2 counters take 2
3 counters take 1 or 2
4 counters take 1
5 counters take 2
6 counters take 1 or 2
7 counters take 1
8 counters take 2
9 counters take 1 or 2
10 counters take 1
11 counters take 2
12 counters take 1 or 2
13 counters take 1
14 counters take 2
15 counters take 1 or 2
Nim-17
1 counter take 1
2 counters take 2
3 counters take 1 or 2
4 counters take 1
5 counters take 2
6 counters take 1 or 2
7 counters take 1
8 counters take 2
9 counters take 1 or 2
10 counters take 1
11 counters take 2
12 counters take 1 or 2
13 counters take 1
14 counters take 2
15 counters take 1 or 2
16 counters take 1
17 counters take 2
And so on...
3.Does it matter who has the first turn? Why or why not?
Yes, it does matter because if you are first because if you are first and take 1 you will automatically win since you can follow my strategy above.