I hadn't noticed the tank/stand issue, glad iamntbatman spotted it. That is dangerous. The easy solution is a sheet of plywood, 3/4 inch thick, that will fully support the tank with no such overhangs. The plywood can sit on the stand furniture. That will also protect the furniture from getting grooves in it from the weight of the water; the plywood will absorb the weight.
I don't know that I would class livebearers as particularly easy for beginning aquarists
. If you have male/female, they will reproduce like mad. And some (thinking of mollies) are not good "new tank" fish. However, we can expand on this, and suggest suitable plants; but first, do you know your tap water parameters (hardness and pH)? This will make it easier if you select fish suited to the water. More on this too when we know the numbers. A pH test kit is useful as this is something most of us check regularly. Hardness is not so necessary, as once you know the tap water hardness we will know the pH buffering capacity and hardness is not likely to change in the aquarium depending upon what it is out of the tap. Your fish store may do hardness test; if so, ask them for the specific numbers, and for GH (General hardness) and KH (Carbonate hardness). Alternatively, some water companies will have this information.
When setting up a new tank, you should have the filter and heater set as you intend for fish. Temp at 25C (that's 77F) is fine for a community of livebearers or most tropicals, which ever way you go. The bacterial supplement should quicken the cycling, it is presumably live bacteria, though I don't know the brand you mention. [I take it you are in the UK?] Have a read of iamntbatman's article on cycling at the head of this section, here's the direct link: http://www.tropicalfishkeeping.com/f...m-cycle-38617/
Aside from using a biological supplement, the nitrifying bacteria cycle takes time to establish, anywhere from 2 to 8 weeks depending upon various things. Do you have an ammonia and nitrite test kit? The linked article explains this.
One comment on plants, they keep the water clean, they don't contribute to dirty water. Plants do a tremendous job of filtration. Many planted tank aquarists do not use filters, leaving it to the plants. Some of this is explained in my articles on a low-tech planted aquarium, at the head of the Aquarium Plants section; here's a link to the first of four articles there: A Basic Approach to the Natural Planted Aquarium--Part One
You might want to read through those to get a feel for how easy planted tanks can be.