This is likely going to be closed, but I want to get a short bit of advice in before it is ..
We're designed around the concept of one account associated with many sites, at the moment.
What this means is, should you elect to maintain multiple accounts (not multiple profiles on sites using a single login, but multiple logins that are never associated with one another) .. you must be very careful to not mix them. If you accidentally associate one with another there's a very good chance that the system will merge them, and undoing that is an extremely difficult task that we can't always meet.
I strongly recommend using incognito / private browsing / separate browsers entirely if you want to go this route.
Just a note, in the hopes that you avoid an unfortunate surprise should you do this. Additionally, there's nothing wrong with having multiple accounts (aside from us not supporting it very well) so long as you don't use them to do things you could not do with a single account. This would mean not voting for your own posts, starring your own chat messages, coordinating flags between the accounts, etc.