Exporting video for first time - didn't set sequence settings in beginning?

[#1]

Hi,

I created a video made up of clips of many different videos I downloaded online with fair use or no copyright.  I downloaded most of them using 1080, but some only had 720 available.  Others from pexels were probably higher.  I didn't know to set my sequence before I started, so now that I'm exporting I don't know anything about this and how to set the setting for the best quality.    I watched a video but it seemed they knew the camera settings before they started and started with a sequence setting to match.

I've worked for months on this so I want to be sure to export to high quality.  I will not be putting it online, I am going to upload it to dropbox or save on a thumbdrive. If anyone has any tips I'd appreciate it.

Thank you!

[#2]

What are the sequence setings? 

[#3]

Thankyou for your help. I'm attaching the setting screenshot. I don't know
what this stuff means yet so any help is appreciated this is a gift for
someone.

[#4]

[#5]

if the lowest resolution of source files you're working with is 1280x720, than exporting with this pixel dimension should be fine.  I'd suggest you use the h264 match source high bitrate preset and see if you're happy with the results.