Hey! Welcome to the community!
I can only answer the first question since I make a file for each level using the "LoadGame" Funtion. I recommend it because it apparently will make your game run faster than having one huge file.
As for your first question
1) Make actor "score" (in my case it is coin_score for my game)
2) Click on the "Text" button
3) Type "00000" (or however many you like)
4) Choose a True Type font (lots of 'em)
5) Notice the "soft" option. (I liked it)
6) Click OK
7) Create any actor (for me it was coin)
Click the "Add" button next to the word Events
9) Collision>Script Editor
10) Type this in (or paste)
- Code: Select all
coin_score.textNumber = coin_score.textNumber + 1;
11) in place of coin_score you would put the actor that is your score (the "00000")
12) When all is good press "OK"
Now whenever you collide with a coin, the score goes up by 1.