It's a (very) long way and Incognito or similar mode is only the beginning.
A term "secure browser" on default settings simply doesn't exist. Anything stock is designed to fulfill the background purposes of its developer, many of them are purely commercial. Look at what Opera has done to its PC version and how many of your otherwise carefully adjusted settings have defaulted to ones after update where you can be easily tracked.
One advice from me - use Mozilla or Mozilla-derived browsers such as Waterfox. Download and explore in deep the following extensions:
- uBlock Origin
- Smart HTTPS
- CanvasBlocker
- Privacy Badger
- Decentraleyes
- uMatrix
- Chameleon
- Cookie AutoDelete
- Anti Ad-Block Blocker
- Location Guard.
CanvasBlocker is a must to explore and fine tune the browser APIs. Use basic settings in Chameleon too, it's easier.
Never use Google products such as Google, Chrome, do not log into YouTube when using it (unless when uploading something). The most privacy-friendly search engine I have found so far is Searx. Instances such as searx.xyz or searx.rocks will index and show you everything from Google, DuckDuckGo and Start Page without tracking, using POST instead of GET, and if you return to the results it will tell you they had expired.
Not certain about using a VPN, unless paid in bitcoin/crypto, as you simply tell the secret services this is my name, these are my bank account details, they are linked to this mobile phone number and physical address. You do not need to track me permanently - what you need to do is just contact the VPN provider once a month and get everything I have been doing all at once.
Anyone still believes "hackers" are the ones to be afraid of and not the governments and their thousands of private contractors, data centers and especially created services to spy on you at all times? If you use any sort of firewall you will see that not only companies like E.I. Dupont de Nemours and the Halliburton Company which in theory (oil and chemicals) have nothing to do to spying but also others like Track Data Corporation and Massachusetts Institute of Technology that intercept and listen to your every Signal, Whatsapp or Skype call, as well as Microsoft to their Xerox (Azure) servers. It's all there - there are here for you only. It is not personal, they simply need to know, record and file everything for you so they can use it against you or commercialize you to whoever pays at a later stage.
Do your work yourself, they are there and won't disappear or stop doing what they do to you for ignorant comments above like "you can't do anything against a trillion dollar IMC" or "I have nothing to hide", haha...