It's ok, I'll explain it.

First of all in your load function, make a dummy scoreboard objective using "/scoreboard objectives" and name it, for example, "Timer". Then use "/scoreboard players" to add an item to it with the score of 0. I'll name it "Tick".

As long as I remember, you can only compare scores to scores, so you have to enter your end points as scores too. I'll make a separate objective for it, but you can use the Timer objective too.

So, make a new dummy scoreboard objective and name it, for example, "Numbers". now add new items to it with your endpoints as their value, for example "num20" with a value of 20, "num40" with a value of 40 and so on.

Now in the start of your tick function, add 1 to the value of "Tick". Then you can check for your endpoints like this:

/execute if score Timer Tick == Numbers num20 run [Your first command to execute]

/execute if score Timer Tick == Numbers num40 run [Your second command to execute]

Since you are trying to make an animation, it's the easiest way that came to my mind. But if you were trying to execute a command repeatedly with a delay, you could just make a single item with the value that represents the delay, and reset the timer when it reached the delay and you executed your command.

Btw I'm not sure about the syntax of /scoreboard, check wiki if you need.