Potential graduate advisors get many, many emails from prospective graduate students, so it is not surprising you may not have heard back after contacting them just once.
I would suggest following up with an additional email after two weeks. Don't feel bad about following up as the worst they can say is "no, I'm not taking any students" and then at least you have an answer and you won't keep bugging them!
I would also suggest trying to contact them in a method other than email as emails can get buried in a busy inbox. Some of the best advice I got when applying to grad school (in my field you typically have to reach out and connect with potential advisors and ask about funding before applying, so I did this part first) was to send actual SNAIL MAIL letters to professors. I was told by several of these professors that I ended up connecting with that that made me stand out. You could also try calling and leaving a voicemail if they have a phone number listed on their university landing page.