Hi welcome to the forum
Thats a really nice looking tank you should keep an eye out for our tank of the month competition when it comes to your tank size!
There are a couple of issues with the fish you have but I think you might suspect that.
The first is compatibility. Tiger Barbs are known to be nippy fish so could nip the big fins of your Angels and Guppies, Angels can get quite an agressive fish to each other and other territorial fish like your Gourami. Angels and Gourami often dont work out long term as they both stay in the upper third of the tank and are both inteligent fish so often maintain a pecking order, sometimes it does settle down but in most cases it doesnt work out. You may need to choose between which species you want to keep. Angels are also very hard on each other if they do not choose to pair off together, though in a tank this size you could be ok. The other aspect with Angels is they need a tank with good height - ideally 18 inches between the water line and the sand. They get about 6 inches long but also 6 inches tall so you need to give them space to move up and down the tank more so than other fish that are more rectangular.
You have a mix of fish that live in hard or soft water - eg garra, mollies, guppies need harder water and rummy nose, angels and corydora need softer water. Keeping fish in the right sort of water really increases their life span and decreases their risk of getting ill so its worth bearing in mind. Do you know your water hardness? If you dont have a test kit this info is usually available on your water companies website. The best situation is to sometimes have neutral water as it gives you the broadest range of options for the fish that will do well in your tank.
The last thing to think about is numbers, you have a lot of fish that are best kept in schools. Tiger Barbs, Corydoras and Rummy Nose are all schooling fish and you are best off keeping them in groups of at least 6 but 8-10 is a better minimum. Your Gara and Yoyo Loaches are gregarious so while not schooling do appreciate being in decent numbers, 5 or so would do for both.
Wills