Also can someone explain to me why people say the dollar will collapse and what that means?
Your OP message is a huge wall of text, so I'll try.
First understand what is a bank, and what happens if you "deposit" money there.
You have loaned your money to an institution. That's right, the bank is not "keeping" your money "safe", and they can default on you.
Banks are required by the State to keep at least a minuscule portion of the money people
loans deposit to them. This is basically a legalized ponzi scheme, should the clients start withdrawing at the same time, it doesn't have enough money to pay all their debt, thus they can default.
To mitigate this, the Central Bank was created. A bank that can loan to banks so they can (hopefully) survive some crisis.
It doesn't end there. If you "deposit" 1000, with the magic of fractional reserve (lets pretend its 10%, its actually even less in some countries) how much money is added in the system? 10000 (your 1000 is the 10%, 9000 90% from nothing).
Aaaand, the bank can loan from that 10000 to, lets say 10 more people, 1000 each and they as well "deposit" to the bank again.
How much money was added to the system? 100000, this goes on and on. When we say its a legal Ponzi, we mean it.
It all started back in the day, when banks were banks and not a single coin of gold could leave the coffers without permission, lets say 18th century or earlier. This "safe storage" service had a cost, naturally, you have to pay the bank to keep your money safe (not the other way around).
A banker one day saw all that money lying there and though, what he if borrowed a bit in secret, invest it, and then return it before the owner learns about it? Well that was a crime back then, but they still did it and got rich. And used their money to influence politicians so that the scheme would actually be legal, and that's modern banks.
Its not just the "State" that can "print" more banknotes, when banks receive money, they too can create "money" out of nothing. Sooner or later a crisis comes that brings at least one or more banks down, because like any pyramidal scheme, it can't survive if everyone stops injecting money to it.
Do you still trust fiat? There is no way you as an individual to verify how much "money" is in the system, but real bitcoins are only the ones in the blockchain (sidechains and "custodial" wallets is reinventing virtually what banks do, oh and nfts and other blockchain spam are the modern tulips) every "coin" is accounted for, and its finite. You don't have to trust someone giving you a paper that says "valid for N bitcoins cash at this Lightning Node / Exchange, whatever".
The way you do it without fiat in the bank is simple: Only keep a small amount you need in there for daily / monthly use. You don't need 50k in the bank for daily/monthly needs, do you? Just keep a small amount and if fiat collapses you still have your still valuable bitcoins which you can still sell in small amount to keep doing things in your country that still won't recognize Bitcoin as legal tender (or move to El Salvador and be done with it).
Can the USD collapse the same as the Zimbawean dollar, Venezuelan bolivar or Argentine peso did? Of course, the problem lies in all fiats, the only difference is better countries have better economies (and a bit less idiotic politicians) which gives them some extra leverage, but again, the problem is inherent in the system, it can fail. Both Trump and Biden had their administration print money to acomodate aids for the pandemic, which is called devaluation elsewhere. Politicians always think it is a "necessary evil", that they can take it "with moderation", and then do it again and again, because they can...
At the same time, banks and other financial institutions often go even more aggressive and crazy doing "investments" that would normally not be done, and/or under a false pretense product of State direct intervention of the economy (like manipulating interest rates) which is the direct cause of the economic cycle of bubbles and bursts (read about the "Austrian" school of economy at mises.org).
And these constant cycles often cause panic having people withdraw their money, and if you learned the above, you know more than 90% of the money in the system doesn't exist, so only the first ones will have their cash, politicians panic and set the volume of the money printing to 11. This is essentially the story of all Hyperinflation cases in history. They have the power to destroy your wealth as long as you hold their money. Inflation is the most tyrannic of taxes.
All that being said, don't get in debt with the system to get more bitcoin, no mortgaging or other nonsense. Quite the opposite, slowly get rid of all debts if you still have some and never again get in debt (this permanent debt is what the monetarists / "Chicago" school of economy desperately wants you to do, or their system collapses).
Instead save your own money in your own bitcoin wallet. If you have a fiat income, leave in the bank whats needed for your needs and exchange the rest. You can diversify with other things you could sell later, like property, art, etc. Just don't keep everything in fiat. Rich people don't buy luxury stuff just to show off, that stuff can be sold later for a decent value unlike a fiat that would be worthless.