New Tank Purchase

This is my new tank I have not set it up just yet because I am doing as much Research as I possibly can but if anyone wants to give me any ideas about what I should do with this I would be greatful! I am kinda digging a light colored sand substrate and I have to keep in mind that most likely the fish I have in my 3 gallon (2 guppies, a mollie, a dwarf frog and a khuli loach) will most likely be moved to this tank if that gives you an idea of what my plan will be for fish.
Thanks!

A 20 gallon tank is a great size to get into the hobby with.

I'll have to give some thoughts. There is lots to think about - so I'll just start at what comes to my brain first.

I am curious about the filter- and will have to have a closer look at what comes with it (if you have some information on what type of filter this is - it could be helpful). Many filters than come with aquarium sets will push their filter media (the stuff in the filter) in an attempt to keep you buying things. Often hobbyists will replace some of this media (especially if they have charcoal packs, or "ammonia removing" media - lest they get spent and/or start leaking back into the tank).

Really there are 3 main types of filtration for an aquarium - mechanical (this is what the sponge type material does - this takes out the little bit of particulate in the water), chemical (which is what charcoal is often used for) - but honestly isn't really an important thing and can be frustrating to maintain (often this only gets used to remove medications from the aquarium etc), and then biological filtration (which is the porous ceramic type materials - they are porous because it provides more surface area for the beneficial bacteria to multiple/grow). Many people will take their chemical filtration material out and replace it with either more mechanical filtration (e.g. more foam/sponge) and/or more biological filtration media. Ultimately this is better, and cheaper.

Somethings to consider - Khuli loaches can be a bit challenging (I actually keep dwarf chain loaches). Ultimately it may be best to have a small group of them (ideally probably 5 or 6 again)- but you'll obviously want to be patient for cycling, and not overloading anything. They prefer to be in groups, and can be quite timid otherwise. They also have sensitive sensory organs near their mouth called barbels (many fish have these - other notables are corydoras - a genus of small freshwater catfish commonly kept in the hobby). These barbels can get damaged if they substrate is not smooth, so sand or very smooth small gravel are good choices. So I think you are on the right track there!

Other things to think about - do you want to have any live plants in the aquarium?

For this tank I hadnt purchased anything other then the kit so far where Im still in the research phase but I was thinking of live plants but I definitely want to make sure I do it right so they survive too lol I seen a video about pothos being a great aquarium plant...thats about as far as I have gotten with the live plants thus far. I would like to go a little more natural looking with the sand substrate that I had mentioned I was thinking of going down home to find a nice piece of driftwood from the beach but I have gotten different advice on what I should do to make sure Im not introducing anything to the tank that would cause issues because it would be a salt water beach and I would be setting up a freshwater tank.

Salt water driftwood usually isn't a concern.  When you compare the volume of the wood to that of the tank...and then consider the much smaller volume of water that the wood might absorb...the dilution of the salt trapped in the wood is very unlikely to even approach what many consider a prophylactic dose in a freshwater tank.  You can also soak the wood in a few changes of freshwater before use, which will remove a large amount of whatever salt it may contain, and will also speed up the process of getting it to sink.

I always collect my own driftwood and rocks, and sometimes even fine gravel or sand off a beach.

Hoping your tank is coming along Shawna .

Some other plants that you could consider would be java fern (widely available - good for low light) or various species of aquarium plants from the genus Cryptocoryne are also quite population (and low light). Good to do research with what works though - for beginner hobbyists - generally plants that will survive low-light setups without CO2 supplementation are optimal. If growing even low light plants - many people upgrade their lighting.

Salt water driftwood can contain a lot of different microorganisms - most of which wouldn't/shouldn't survive such a transfer - but I am personally a bit hesitant. If the wood has been waterlogged - it may take a lot of soaking and boiling to reduce the salt content. This is a fairly small tank too - so I'd be careful.

Alternatively, there are options in many LFS for driftwood (e.g. something like spiderwood is quite attractive - albeit sometimes somewhat pricey). Mopani wood could be another option - quite dense and often sinks without much prep.

Perfect good to know I will post once I have started the process!