Is Aves FIXIT® Sculpt the best thing for beginners to use?

I think Milliput would be better for you in general

If my options are Green Stuff and Milliput which should I get?

I knew I was forgetting something,

don't forget milli-put. it is fairly inexpensive, availabe at most hobby stores and it has a similar cinsistency as aves. It has a longer cure time and does not hold detail as well as aves, but it will get the job done. it comes in different varieties, white, fine, regular...This was the first two-part clay I ever used, and with pretty good success.

It does! Thanks!

Here is a list of sculpts and there various uses and where to find them,

Aves Fixit sculpt, it can be bought online or special order from some shops but I've never found a shop that stalks it year round, I consider it to be the best sculpt out there because it is very easy to work with and can be smoothed using water and cures very sturdily on the down side it is very expensive.
Aves Apoxie sculpt, it can be bought online or special order just like fixit, it is pretty sturdy, slightly less expensive then fixit, it comes in many colors, the only downside is it doesn't work as well with water but there is a special smoother you can buy.
Super Sculpy, it is pretty sturdy and very inexpensive, and can be bought from most craft stores, it is pretty easy to work with, the downside is it needs to be cooked and this can warp or melt the plastic figure you are sculpting on.
Normal Sculpy, this can be bought at most craft stores, comes in a wide variety of colors, and is very inexpensive, the downsides are in my experience it can be hard to work with and it needs to be cooked same as super sculpy.
Green Stuff , it can be bought online or special order from some shops, it is pretty easy to work with and not that expensive but the real drawing point for me is that it cures slightly bendable which is great for sculpting thin parts on figures,
Zubber, it is made for kids and can be bought at Walmart or Target or online, it cures completely bendable and is great for sculpting details on capes or loin cloths, it is very hard to work with though and needs to be cooked to cure although they advertise that it cures on it's own that hasn't been my experiance (I use a heat gun to cure mine), it also comes in multiple colors that can be mixed.
Epoxy Putty, can be bought online or special order from some stores, it is great for sculpting large parts of figures but not so good for detail work, it's pretty sturdy and not to expensive,
plumbers putty, it can be bought at wall mart, target, alco, K mart, a lot of gas stations, any hardware store, and a lot of other places, it's cheap to, it's a clay made for patching pipes so it's super sturdy, and can be sanded into any shape, it holds detail pretty well although sometimes there are hard chunks in it, the setback to using it is it cures in 5 minutes so you only have 2 or 3 minutes of working time which makes doing a good job very very hard.
Milli-Put it is a two part clay, and is fairly inexpensive, available at most hobby stores and it has a similar cinsistency as aves but has a longer cure time and does not hold detail as well as aves, but it will get the job done. it comes in different colors, white, fine, regular. It's price will vary slightly depending on color.

I hope this helps answer a commonly asked question