My wife and I do the Suwannee river 50 miler each year.
The portage around big shoals is as follows (but this can change due to high water).
Take out is on river left. There is normally a tiny beach about five or six feet long. then a few feet of shore line before coming to a steep about four foot high embankment. If you are by yourself, just get your bow up to the top, and then it is an easy climb up on the right side. Then pull your boat up.
Once you are up there, the trail is nice and easy. It is mostly soft pine needles over hard packed sand with a few pine tree roots here and there. It is about a quarter mile or less long.
Unfortunately there are several places to put back in and you'll have to scout off to the right to find the best for you. They are all steep over slippery shale, so when you find the one you want, you will have to take your wheels off and slide the boat down
We usually take the large trail to the left and after several hundred yards bear to the right and ease ourselves down a slippery but doable embankment. It ends where a small side creek flows into the Suwannee.( it is also the last place to put back in)
Caution: the main trail continues off to the left after this area away from the river, so if you feel you have gone more than about a quarter mile, make sure you back track to find the correct way.
On Little Shoals: Hopefully you will have decent water, and just run them on river left. They have never presented a danger to us. If the river is low, you might run aground or have to pull you boat through.
I sure hope you have decent water above Big Shoals.Several times we have encountered shallow water
Gator Baits Mate (AKA Jack L)