Different countries will have different laws on cryptocurrencies and Bitcoin. For example, in many countries, Bitcoin is treated as property, and you will be very likely to have to pay tax on it, and for converting your Bitcoin into another currency.

But, in some countries it is legal to use Bitcoin as a currency, and in some countries it is illegal, especially in China.
It is possible, however, to hold or move Bitcoins as you please, particularly when they are stored in a non-custodial wallet. The government cannot access your Bitcoin wallet to seize your Bitcoins if they are stored in a non-custodial wallet you own. That means, government will not be able to restrict access to Bitcoin that is stored in a non-custodial wallet you own.