This Minecraft command Block tutorial is how to give players points as they play on your server to allow special shops or perks for people who play a lot on your server

/scoreboard players add @a TimePlay 1

/execute @a[scores={TimePlay=100}] ~ ~ ~ tellraw @s {"rawtext":[{"text":"You Have Earned 15 Points"}]}

/scoreboard players set @a[scores={TimePlay=100}] TimePlay 0

/scoreboard players add @a[scores={TimePlay=100}] points 15

Videos Below Of How It Works
https://youtu.be/LlnzWNHxDpM [video=youtube_share;LlnzWNHxDpM] https://youtu.be/LlnzWNHxDpM [/video]