There is research on the most profitable type of real estate investing in terms of limited budget https://tranio.com/traniopedia/tips/high_yields_on_real_estate_where_to_find_them_and_what_to_know/. It says that a short-term rental property would make you a stable and high profit – about 5% yield. To minimise risk, you can use the services of professional management companies (this costs 20−25% of the total rental revenue), the expenses will be rewarded with higher occupancy rates. The best choice is a one-bedroom apartment in the center of a big european city.