Hi! I am currently trying to learn and understand about how to invest in Forex, and have signed up for a Demo account on one of the Forex Brokers (ig.com) in Singapore. I have the below questions, can those with experience please answer?

Demo accounts are free!
Fees charged by brokers: Spreads and Overnight Interest
If you are looking for a free course that will take you from beginner to advanced trader I recommend you check out Tradinglive.

Personally, I use OANDA and I think the interface is relatively easier to use and the fees are also rather transparent on the website!

You should think about what kind of trading do you want to do. What is the time frame you are looking at? Are you doing day trading or do you intend to hold it for a couple of months? If you intend to hold, then take note there will be financial fees for holding your position every day and it may eat into your profits.

You may start trading with any amounts of money because leverage will allow you to enter in bigger positions that your principal and basically, gain more with less! However, it is important to not enter trades that is beyond your capacity to pay.

You may start with demo accounts and paper trading to try out different strategies first :)