So I've been wanting to make an animation in scratch but with out youtube tutorials so I need tips

It “REALLY” depends on what your needs for animation are. There are multiple solutions in this case.

The most “simplest” form of animation is basically this:

when flag clicked
forever
next costume
wait (0.25) seconds
end

However, you can also have “very complex” animations. Some examples being list based animations, or variable based animations.Though you can use custom blocks to make complex code to make your animations scripts more simple.
For example, you could have this

when flag clicked
forever
animate () for () frames
end

define animate (a) for (b) frames
repeat (b)
switch costume to (a)
end

For this case, you would use the switch costume block and a repeat block to count the frames you need your animation to play for,

I don't understand can someone help me?

umm I want to make a good animation

how do I do it ?

Try to make a storyboard first to plan what it gonna look like and what it gonna do. Then make the animation as costumes in scratch editor. Remember! Scratch does 30 frames per frame. Which means 30 drawings for one second. Then just add this script

when green flag clicked
switch costume to [1 v]
repeat (frame count)
next costume
end

If you want to do less fps (for example 12) do this:

when green flag clicked
set [fps v] to [12]
switch costume to [1 v]
repeat (frame count)
wait ((1) / (fps)) secs
next costume
end