2 Questions: good export and out of sync

Hi!

(first time video editing)

So, recently there was a play at my church and I have recorded it in Full HD 30fps with a Nikon D7500 DSLR

Now, the whole video is almost 1hour long (56min with lots of texts that I added)

When I want to export it, it takes up a HUGE amount of space on my disk and in no means easy to share the video with other people.

What would be the best way to export this video, keeping it in HD with its 30fps?

Generally it is to share via USB stick to other people, so I think keeping it under 4GB would be nice?

So they can watch on there TV or computer or whatever they prefer.

I am not sure, but it might end up on youtube, but ofcourse I could export it again for that under different values.

1 thing I also tried is lowering the bitrate to 10, this brings the video from 12GB to 4GB, but of course, seems to decrease quality.

out on sync:

The sound has been separately imported, and it is good in premiere pro, but out of sync in the export ( i tried a 3min cut from the video)

How do I fix this?

I also notice the subtitles I made are bit out of sync, maybe all is correct but the video itself is a bit out of sync?

And the sound is also a bit 'silent' , but increasing the db's results in more harsh sound?

Thank you in advance!