Church ceremony!

Yes yoy invite everyone to both. If people are driving, they can drive themselves to the reception. If it is far and they are able to leave their cars at the church, you can get a bus

Church ceremonies with receptions to follow at a separate, nearby location are very common. You don't need to provide transportation for guests to the reception unless either site is remote or difficult to get to for some reason. And it's considerate to make sure the travel time between the two sites isn't more than 30 minutes.

Why wouldn't you invite everyone to both? I don't really understand that question.

I don’t think you need to , many people go to reception,
Mostly the closest relatives and friends attend the ceremony, but if you have no limit on seating , then that’s up to you , ppl will decline or just show up for reception

Everyone invited to the ceremony is also invited to reception and vice versa. There is no situation why that would different.

Guests are able to transport themselves. I have never been offered transportation as a guest and was able to get to the reception easily with just the directions card.

Everyone should be invited to both. Guests usually transport themselves from the ceremony location to the reception location. I would just make sure the reception location is a reasonable distance from the church. For my brother's wedding, the ceremony was held at the church and the reception was only about 10 minutes away. The bride & groom, the bridal party (including myself), their significant others, parents of the groom, mother of the bride & her boyfriend (father of the bride didn't attend the wedding), and siblings rode on a trolley from the ceremony to the reception.

Everyone should definitely be invited to both--you can't invite someone to the ceremony but not the reception! But I don't think you'd need to provide transportation from the church to the reception venue, unless it's over a 30-minute drive. Guests can drive themselves

Everyone who gets invited to the wedding gets invited to the reception. Your guests provide their own transportation.

To answer your questions:

Do we invite everyone to both? YES!!! Everyone who gets invited to the wedding gets invited to the reception

How do we handle transportation to the reception? As long as the drive isn't unreasonably long, you don't have to do anything. Your guests can drive themselves

Absolutely you invite everyone to both. As long as the church and venue are not more than MAX 30 minutes away from each other, you don't need to do anything. Just give everyone the information and they will figure it out. The only caveat I would add is if the wedding is a destination/location where the majority have to travel long distances or they don't have access to Uber/Lyft/etc it might be nice to provide a shuttle or something, but not necessary.