I am not sure I understand how TLS works correctly. To my understanding trusting a certain website's certificate is all about trusting that website or not, but the questions below suggest that trusting ONE certificate would put everything you do online at risk.

My college is forcing me to install their SSL certificate. How to protect my privacy?

I can't access websites that use HTTPS, instead getting the message “your connection is not private”!

I have trusted self-signed certificates more than once from many websites because they simply can't afford to pay for a certificate. Does this mean everything I do is vulnerable to MitM?

I am not sure I understand how TLS works correctly. To my understanding trusting a certain website's certificate is all about trusting that website or not, but the questions below suggest that trusting ONE certificate would put everything you do online at risk.

My college is forcing me to install their SSL certificate. How to protect my privacy?

I can't access websites that use HTTPS, instead getting the message “your connection is not private”!

I have trusted self-signed certificates more than once from many websites because they simply can't afford to pay for a certificate. Does this mean everything I do is vulnerable to MitM?

I am not sure I understand how TLS works correctly, to my understanding trusting a certain website's certificate is all about trusting that website or not but the questions below suggest that trusting ONE certificate would put everything you do online at risk.

My college is forcing me to install their SSL certificate. How to protect my privacy?

I can't access websites that use HTTPS, instead getting the message “your connection is not private”!

I have trusted self-signed certificates more than once from many websites because they simply can't afford to pay for a certificate. Does this mean everything I do is vulnerable to MitM?

I am not sure I understand how TLS works correctly. To my understanding trusting a certain website's certificate is all about trusting that website or not, but the questions below suggest that trusting ONE certificate would put everything you do online at risk.

My college is forcing me to install their SSL certificate. How to protect my privacy?

I can't access websites that use HTTPS, instead getting the message “your connection is not private”!

I have trusted self-signed certificates more than once from many websites because they simply can't afford to pay for a certificate. Does this mean everything I do is vulnerable to MitM?