I recomand start with some episodes of the clones wars, but not the whole series. but you dont have to see them
but start with this movies 4(a new hope) 5(empire strikes back) 6(return of the jedi) . then episode 1(phantom meance) 2(attack of the clones) 3(revenge of the sith), solo, rouge one, 7(the force awakens) 8(the last jedi) 9(rise of skywalker).