TL;DR: Although I know all the things I want out of an online investment platform, I have no idea how to find which platform best offers those things.
I have spent some time organising and planning my personal finances but am a total beginner when it comes to investing. After researching and referring to my personal situation, I have decided that I want to pick an index fund that neither looks too stagnant nor too volatile, invest my 30k in it pull it out/re-assess in 5 years. I know that I'm looking for simplicity, I am no expert so any detailed options and tools for managing money will be wasted on me. The entirety of my interaction with this platform will be to create an account, review index funds, pick one, invest 30k in it, look at the progress a few times over the years to feel good about myself, then take it out 5 years later and (possibly) never touch the platform again. I want medium risk/return. I am 22y/o living in Australia.
I've been told to "choose the platform that works best for you" but in browsing these sites: StockBrokers Article, Finder Comparison, Mozo Article I realised I have no idea what my goals mean in terms of a trading platform or how I might start to figure out which of these platforms would "work best for me".
Some aspects are fairly self explanatory. Generally positive reviews is good. Some mention of simplicity in the description suits my needs and seeing mention of cheep costs or good returns/rewards I think is good, but here is where my understanding pretty much stops. Although I can tell you every interaction I plan to have with the platform I don't know if a $100 bonus for signing on will save me more money or less than an extra $2 (or .1%) brokerage fee. I don't even know if what I am doing counts as more than one "brokerage".
The finder comparison website compares stats such as: Monthly fee, Standard Brokerage Fee, Margin Trading-Online, IOP's/Floats, International. But since I don't know which type of fee's I need to prioritise on minimising, or if higher fees somehow equates to a better service, basically, none of the stats really mean anything to me at this stage.
How can I go about choosing and comparing investment platforms? What are the essentials I need to understand in order to make an informed decision about which platform I use?