dual enrollment

Oh cool, I literally just sent my dual enrollment transcript yesterday. You should have a college or dual enrollment counselor, it's just whoever has been sending you emails from the college. And you can ask them.

However, what they will probably tell you is to go to your dual enrollment portal, and just search around for something that says "Send Transcript". Usually, it's connected to the Registrar's office, so look under a registrar tab maybe. You can also email that office. But you will have to fill out a form and pay a small fee for each place you send it to. For my college, it was $5. You cannot send them via the common app.

Also, it looks like you are still applying to colleges. You should not be sending your dual enrollment transcript to every college you apply to. You only need to send it to the college you commit to, after you have submitted your deposit, and are enrolling in classes.

"How will they know about these really cool classes I took with a COLLEGE with grades I worked really hard on then?" you may ask. Well, the courses and grades from dual enrollment should be included on your high school transcript which IS sent to all the colleges you apply to. If it isn't already on there, contact your high school counselor. Mine just needed a screenshot of my grades, but yours might need an unofficial transcript from the college (which you should be able to get for free by just emailing them) or an official transcript which you will send to your high school in the way I talked about above.

As far as your last question, I think they'd both be fine. I doubt it will matter a whole lot. Go ahead and check the colleges you are applying to to see how many outside credits can be applied to your major (so if you are majoring in biology, you might not want to take ALL of your courses in that field, or you might really want to if your college doesn't have any limit placed on stuff like that and you can skip a year of college maybe). Some college have very strict dual enrollment policies where credits only count as extracurricular, do not count towards any college requirements (i.e. freshman GED), cannot be used to fulfill your major's course requirements, and will not count towards your college GPA. In this case, they will literally just be listed on your new college transcript and do nothing else. So just do some research!

I hope this helps, and good luck!

Like @EssayMan mentioned, your high school will be sending a transcript to any colleges you apply to which will have all the college courses you took on it. Who helped you set up the dual enrollment classes in the first place? There should be someone from your school involved in the process who can help coordinate things with you if you are concerned you might not be doing things right. Most likely you'll just need to request your transcript from the college and you'll be fine.

In terms of how elite colleges look at your transcript you should aim to have a "spike" in a certain area, usually one you're most passionate about and want to pursue in college, and then preferences for some other areas that you might not be as passionate about or don't have time to commit to 100%. This way you can show you excel at something particular but you also have other interests/passions rather than showing colleges you are ok in a lot of different areas. Maybe check out this livestream: https://www.collegevine.com/livestreams/4102/finding-your-spike-with-elias, it might be helpful. This one might be helpful too: https://www.collegevine.com/livestreams/507/how-to-build-your-extracurricular-resume