Welcome to the forum. Are you after tips on aesthetics or more technical, relating to plant growth etc?
I would suggest a finer substrate or some pockets of finer substrate so you can remove the plants from the rock wool and get them to root at the back. Maybe add some depth, using smaller foreground plants.
Welcome to UKAPS.
Perhaps post any questions you have in the relevant sub forums where they will be more likely to be answered
Fish in cycling is a contentious issue, but having two goldfish which produce a lot of waste and will very quickly outgrow the current tank is not ideal by any means.
I would look to rehome the goldfish and choose some more suitable temperate species such as White Cloud Mountain minnows for your tank.
The plants need removing from the pots and planting in the substrate. You may need to look at adding some finer grade gravel or aquatic soil to allow the roots to develop better.
If you post in the relevant sub forum you will be able to get specific advice on all of the above subjects along with additional information relating to co2, lighting and fertilisation.
Hi, I can only add that the goldfish will make keeping a planted tank harder as they regularly taste soft leaved plants and you will need robust filtration, or lots of water changes, to keep algae at bay. White cloud mountain minnows would make the learning process easier for you. It might sound like we are anti goldfish but the easier you can make looking after the tank to begin with, the more likely you'll enjoy it.