You can do it old school, the way they taught you in your engineering courses. One classic homework is to proof/derive the transformer dimensioning equations, so you don't forget them.
The ripple voltage for a bridge rectifier circuit is
With
Iout the output current through the output load
RL, smoothing capacitor
C, AC frequency
f and internal transformer resistance
Ri.
If you then start to simplify by choosing/assuming a transformer where you have
you get
You specify a maximum ripple you can accept, and solve that equation for C.
If you are into simulation you can then use the values as a start for a simulation.
In reality you use a few more equations to calculate required transformer properties (which I am too lazy to look up), which in turn requires to solve a non-linear equation system, which you typically do via a relatively simple iteration in the particular case. And again you can plug the result of the iteration or just an initial ballpark estimate into a simulator if you like.