Yosemite visit

If you like to spend time in California there is a great resource, the book California Camping by Tom Steinstra. It has the information by geographic area with regional maps so you can look and search campgrounds around Yosemite instead of like the Woodalls and similar directories where you need to search by town and bounce for one section to another.

Current information on campground facilities, length of campsites and numbers at a given length, scenic rating which is a big help as you may find 3 campgrounds in an area but 1 is much nicer with better views or may be closer to a stream for fishing, etc.

There are length restrictions for the road to Sequoia.
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On 198 (Generals' Highway), yes, but not on 180.

There are length restrictions for the road to Sequoia. Try here for an overnight with close access to the park.
Sequoia Rv Ranch
If you drive from Yosemite you will want to park and see Sequoia the next day.

Well, we "day trip" over 100 miles many a time up in Yellowstone and Grand Teton National Parks. We park the FW in Colter Bay and then get up early in the morning and drive to Yellowstone, it's about 45 miles to the south entrance and then tour the park and come back home. Having done this for many years, we kinda know what we want to see. I would suspect that this trip might be a stretch, but will probably try it anyway. Otherwise, if it seems too far to be comfortable, we might just find a campground around Sequoia for a day or so while we look it over. We will leave from there and go over to the Palm Springs area and see some friends there and take in the Living Desert there as well.

"We also plan on dropping down to the Sequoia Park on a day trip"
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This is a long 'drop'! Yosemite and Sequoia-Kings Canyon NPs may look 'close' to each other on a map, but they are not, and choices of routes between them are limited, and they're not fast.

Depending on where you end up in the Yosemite area, you'd have to come back west on 140 to 99, or west on 41; either way, you'd take 180 up to Sequoia. This is a good road, but it's winding and a haul up to the park. (There is no eastern entrance to Sequoia NP, and even if there were, you'd have to go across Tioga, then down 395 to access it.)

You might want to re-think this 'day trip' idea! ;)

May is a very popular month for camping there and the campgrounds, in the Park, usually are booked by February.
so, even if you plan on staying outside the park, you may need to make reservations.
and it's a long drive to the Valley, from any outside campground.

I have tent camped in Yosemite for 20 years or so. This time using Upper Pines, in a Class C. Bears are always there. I don't see in your profile what rig you have, so I can't make any recommendations.

The roads around there are full of curves. Don't expect to zip anywhere quickly.

We're going to Yosemite sooner, but the web page gets updated on the road conditions.

You don't give your route, so I assume that you will be coming from the south. To have more time in Sequoia, I would suggest a stop in Visalia or Fresno for a day trip to the Park.
I have stayed at the Yosemite South / Coarsegold KOA in Coarsegold, CA before it was a KOA. Not the best, but worked for us at the time because it was free.
Also have stayed at the Bass Lake RV Resort in Bass Lake, CA. Membership park, but I think open to the public.
While eating at the fabulous buffet at the Chukchansi Gold Resort & Casino in Coarsegold, I notice that you can dry camp there for a few days.
If you are going to be on the west coast for any length of time, I would suggest that you look at the Thousand Trails Zone Pass. You can get two zones for $525. 30 days free camping, then $3 per night. There is TT park just outside Groveland, CA about 5 miles from the Yosemite Park's entrance. Then a beautiful drive into the Valley and the rest of the Park. A weeks stay at a commercial campground would almost pay half the cost.