5) Download an app called "CoinGecko" if you want to track the price of BTC and other crypto. It's a nice addition but not essential
I would advise exact opposite of that if you are starting your hodling career. There is no need to have any sort of app on your phone if you plan to hold for longer period of time as it may only distract you from your goal and you might be tempted to panic sell once BTC starts dumping and these things will happen occasionally during your hodling career.
I joined the hodl club sometime in the late 2018/early 2019 and one of the first things I did was to remove Blockfolio app from my phone. I simply stopped worrying about current BTC price and fluctuations and focused on the long term goal.
I put all my btc in coinbase, is it safe?
No. Not your keys, not your bitcoin.