In which currency is my profit calculated?
Different instruments are traded in different currencies. For example, commodities (like Gold, Oil, Silver) are traded in USD, stocks and indices are traded either in EUR or USD depending on the origin of the instrument. As for currency pairs (like EUR/USD), profits and losses are calculated in the second currency of the pair. If your account is in a different currency, then your profit or loss will be exchanged in real time into the currency of your account.
Can you manage my account or tell me what to buy or sell?
Trading 212 does not offer advice or Managed Accounts. You alone should decide for yourself what to buy or sell.
Do I have to pay taxes on my profit?
Your profits could be liable to taxation in your country according to local regulations. Usually, income from financial trading must be declared in your individual tax return. Please check with your local tax office.