Best way to do all the bitcoin bullshit you need, while staying anonymous is confusing for most new bitcoin users. I'll give you some pointers and tips tho! First download a bitcoin wallet app on your phone or computer. I recommend Coinbase. Use to use and keeps it simple for anyone. Use your real identity and information while creating this wallet ( I'll get to "making your bitcoins anonymous"). Coinbase let's you link your debit card, credit card, bank account and even PayPal, to buy your bitcoins. Coinbase also has some of the lowest "fee's" related to buying and moving your bitcoins. After you get your first wallet, you should "create" a second, new wallet, from a different provider, under an alias. You can use Blockchain, Bitcoin.com etc. this allows you to send your bitcoins bought under Coinbase and your name is attatched to that. After you transfer your bitcoins to your second wallet is where it might get confusing.
I recommend doing what I personally do. I created another wallet that I can use and is able to function on the "darknet" or deep web. It's referred to as an anonymous online source. People can only access the darknet over a TOR network. All websites addresses all end with a .onion. For example if this website was on the darknet, it would be musclechem.onion (not a real website btw). Another point I want to mention to you is just How important it is to do your homework, and use different tools to protect yourself over a TOR network!!! #1 priority!! Things like hiding your IP address with a VPN service is a MUST! They have free ones out there but, like the real world you get what you pay for so choose wisely! After getting a 3rd and final wallet, your going to need to "wash" or "mix" or "blend" your bitcoins. This means sending your bitcoins through a service or website that "mixes" your bitcoin transaction with others and then spits "clean" untraceable coins to whatever destination you choose. I use a mixing service between my 2nd and 3rd wallets. I'll send bitcoins through a service and it gives me clean untraceable bitcoins ready to use for whatever I need.
im kinda all over the place and don't have the patience to type a huuuge reply so... but the one thing I truly recommend is obviously doing your homework but also, useing tools and apps and websites to secure myself and cloak my IP address. This makes it harder for LE to track your spending. Also, the more movement between your bitcoin wallets the better. Anyone can look up any bitcoin transactions through blockchain.com so the more transaction the better it is for you. If you do everything that I mentioned, and take the extra time to setup and buy and move and use "fog" to mix your bitcoins the better off and move safe you are.
My end result after taking all these steps is I end up with clean untraceable bitcoins in a secure wallet that I can use over a TOR network.
One last thing I want to mention is to notify you that there are a lot of spammers, and scammers out there that do a good job at disguising websites and tricks people into either sending bitcoins to a wallet address that you think you own, but they do! Or it let's them look at what your username and passwords are. So to prevent that, make sure you double check your .onion adress. Make sure your sources and links are correct. One tool I use for this is Reddit. Good website for everything from illegal marketplaces to God. All sorts of good info and reviews on Reddit. Another one to look into for more info on this stuff is Wikileaks. It lists all the .onion mirrors and pages that are popular over the TOR network.
i hope I helped sorry for the long post but I wanted to include as much as I could! Let me know if I can help with anything else bro.