Chances of admission to top 50 university with excellent grades but few extracurriculars [WI resident, 4.0 GPA, 1520 SAT, 34 ACT, <$40k; social sciences]

Okay, so you have 4-5 affordable possible likelies and it means meet-need or a combination of merit and need work financially (ie., you don’t have to “hunt for merit”). Join their mailing lists l?(if you don’t have one create a college email like firstname.lastname.college46@… )
Check your email once a week, open all emails, click on whatever interests you - this is tracked&logged (they can use it to send you more stories or updates of interest… or see that you say you want to major in French&Spanish but keep clicking on CS info.)
AP scores in 3 languages+TEF are plenty. Don’t forget to list them+scores on CommonApp since tou have them.