I own a Sony a1 and a9, for my long lenses like the 200-600 I mount the vertical grip that helps to balance out the outfit. I also hand hold the lens just behind the lens hood, this too helps stabilize the lens.
You really should be able to hand hold the 105 macro without an issue, it is not heavy or big for a macro. I would not put a tripod foot on the macro, too cumbersome. I reverse the tripod foot on the 200-600 so it is easier to handle hand held.
I am 76 years young and have no issues hand holding my equipment, I also own the Sony 600 f4 and hand hold that without issue.
I find a tripod and monopod slow me down in wildlife photography. Below is an image taken of three Cattle Egret chicks and mom, hand held, at a 100 yards, with the 600mm f4.
I find my minimum shutter speed to be greater than 1/2500 sec. that way it helps hand holding and for birds in flight.
Good luck and keep on shooting until the end.

Thanks for the shout out.
Unfortunately we are heading back to Pennsylvania on April 30th and must say goodbye to out Florida home for 6 months.
We have been very fortunate to have a pair of Wood Duck at Green Cay this year. No chicks yet but lots of opportunities to get close ups of these reclusive ducks.
This post is of a female Wood Duck and the only surviving chick from 8 to survive at Peaceful Waters in Wellington Florida.
We are hopping this little guy grows up and reproduces close by.

Buy the camera and lens(es) you can afford. Although DSLRs are still being sold 'new', they've all been discontinued, whether the manufacturer says so publicly or not. You can get a used or refurbished camera for far, far less than buying new. Certainly, don't spend 2024 money on a 'new' camera first released 4+ years ago and now discontinued. Modern camera equipment is all built for extended use, even the entry-level models last for 10+ years. The pro- / semi-pro models are built for heavy everyday use for even longer. Buying one of these models, lightly used, could easily be the first and last body you need, allowing for more money to be spent on lenses.

Here at UHH, the focus is mirrorless full-frame cameras: digital technology marvels with sensors the size of 35mm frames of film. Removing the space needed for a flapping mirror gives options to adapt most every brand's SLR-style lenses onto that mirrorless body -- MILC - mirrorless interchangeable lens camera -- another buyer value of a mirrorless choice.

What brand is up to you. They're not all the same. But, anyone still selling digital cameras in 2024 has to keep up with the intense competition, where anything less than the tier-1 $6000 models is essentially the same in performance and capability. See if you can find a store where you can physically handle a few options, where one might 'feel' better to you than the others.

Handling some models might also help you decide if an interchangeable lens camera is even what you really want / need. A full-frame model is larger and heavier, even before you mount a larger and heavier full-frame lens. What types of subjects interest you? When you hold that camera+lens, would you want to carry that weight around for 4+ hours, even 8+ hours? Would a pocket-sized model, really about the size of a deck of cards, be a better choice? Depending your subjects, a MILC or DSLR might not be what you want or need.