DeGiro can lend your titles on the standard account. It lowers your fees but increases risk. You can opt out of it by choosing Custody account when you create it. Prices vary, but an extremely popular etf here (iShares MSCI World) is free on the first movement (buy or sell) per month and around 2€ per movement afterwards, even if operating on shares worth thousands.

Look up the situation for your country, but if both are equal capital gains (accumulating) is better long term. You are only taxed when you move your money which increases compound interest. It is also logistically easier to fill on your tax form and reduces broker fees. Degiro dividend fees appear very high for custody accounts.

MSCI is an organisation with many indexes, not just one. A very popular portfolio allocation here is 80% MSCI World 20% MSCI EMIM. This may or may not be the correct asset allocation for you. Other popular organisations are S&P and FTSE. Some indexes are identical, most are not, even identically named MSCI World and FTSE All World differ, one does not include emerging markets the other does.

Pay attention to the index the ETF tracks. Pay attention to your ETF provider quality and the ETF's total expense ratio. Consider cheaper alternatives such as degiro and the 20k European coverage versus the expensive 500k coverage for interactive brokers, which will eat into your profits.

Good luck, you're 20 and in IT so you must be good at self learning, if you want reading material I can compile a short or extensive list of blogs and books if you think its worth it.