grapheneos.org has a lot of info. Make sure to buy a phone with an unlocked bootloader. All carriers lock it so buy it used and make sure that its unlocked or buy it directly from Google. You can install all google apps through Aurora store, a Play Store fronrend. You can also install sandboxed Google Play services so your Play Store apps can run and have functionning notifications, as they usualy rely on Play services. Yes you can sideload apps like normal android. Its AOSP without the google stuff. Some videos/channels: www.youtube.com/watch?v=vh5xjsE4mU4www.youtube.com/watch?v=igSUmfKTXqUwww.youtube.com/channel/UCrG6IID2FX7-GxyKtavRhEAwww.youtube.com/watch?v=L1KZWjZVnAw