Which MS program in biostatistics should I choose, UMN, Yale or UMich?

[Liti]

I graduated from pure Math and math education background and I have gotten admissions without funding from UMN, Yale and UMich. I'm still thinking about getting Phd after master degree.

As an international student, after participating in virtual admitted student event held by UMich, it seems that lots of people asking about fast track from MS to Phd in UMich, however, recently I found that there are lots of people getting UMich ms Biostatistics ad, I think the class size may be almost 40, so I'm wondering how easy it will be?

Also, after listening to Yale's virtual admitted student event, one of the courses which need summer internship really attracts me, but I'm wondering how hard or easy it will be to become Phd after that?

And for UMN their virtual admitted student event is on 26.

Moreover, I also want to ask for suggestions that because I don't have any research background,  how can I become an RA after entering  master program, are there any tips?

if there are people who are now in these programs, I will really appreciate who can share their experience!!

Thank you so much!!