This is a serious problem and if you don't listen and keep the fish in there you will become upset and fustrated but more importantly your fish will die one by one. Look now you might not see it yet but you're damaging your fish and very cruel if you're intending to keep them in there for an early death. These fish have been taken out from their natural habitat from the wide open waters and in this case they have been put into 10 gallons of water which is cruel even at this point. For these fish its cruel because they need much more swimming space for many reasons e.g. to digest their food properly and the clown loach needs to be in groups and all the fish will definitely outgrow the tank.
Nobody likes to be told off but I am not telling you off I'm trying to make you see why this is wrong and I know you're a beginner which everyone makes mistakes at the start because of rushing into this hobby, I have made a lot of big mistakes by not researching so lots of problems kicked in and ended up with floating dead fish. However once I found this forum it made everything a lot easier and more enjoyable because people will give you quick advice and willing to help but only if you show that you're taking this in and acting on whats been said. So now I am relaxing my back and watching my tank in joy. Proiding the right environment for your fish will make them happy and you will start to see more interesting behaviours like breeding behaviours and you might even see eggs or babies in the tank.
The goldfish and clown loach need different temperatures and ofcourse you cannot have 2 temperatures in the same tank.
So lets find out what fish you're after you can choose from coldwater, tropical, brackish and marine but ofcourse I would only recommend either cold water or tropical as you're a beginner to this hobby however tropical will be best as its more fun and you can get different variety of fish. All you need is a heater to make it a tropical setup.
So to make this easier for you to understand I will tell you what equipment is needed for a standard setup. For a 10 gallon tank all you need is a:
Heater - something like a 50 watt.
Filter - any small sponge filter and best make to go for would be fluval.
tank light - any small tube lighting is best that will make your fish happy and will help your plants to grow.
bubble pump - to give oxygen in the tank.
This is all you need for a standard setup.
However your fish will feel unsecure with just these equipment and above and so to make it more like their natural habitat in the wild it would be a good idea to add:
Gravel - any fine substrate would be best as some fish like to dig and they will not cut them selves from any sharp edges.
Plants - this will help oxyginate the tank and fish will feel more secure, the more secure they feel in the environment they are in the more you will see them.
Ornaments - Caves, rocks or bogwood.
The steps you should take right now in order:
1) Take fish back to lfs.
2) Do some research online and from books on how to setup a tropical tank, or after you have taken back the fish tell us and we will give you all the advice you need.
3) Buy the equipment above and decorations to setup your tank also you will need to buy ammonia, nitrate, nitrite and ph test kits we will tell you everything in step 2 so don't worry its very simple on how everything works and we will guide you through it.
4) Cycle you tank - 2 ways to do this either fishincycle or fishless cycle but fishless cycle is the easiest and cheapest way and won't even cost anything.
Whilst then we can talk about stocking your tank.
5) Stocking your tank with fish. It depends on what fish you want and if you don't have a clue then we can give you a list of compatible fish for your 10 gallon tank. If the fish you want needs a bigger tank then its best to upgrade first to atleast the bare minimum of whats required.
Its all very exciting including when you know that you're taking the right steps and making sure that your fish stay healthy, trust me you will enjoy it so much more this way.
Hope you make the right decision