You need a paid membership to Nintendo Switch Online to play course world in Super Mario Maker 2. Pretty sure you could access course world at no extra cost in the original
Nintendo Switch Online Month Individual Membership GameStop, 47% OFF
What you need to know about the new Nintendo Switch Online + Expansion Pack membership plan. - News - Nintendo Official Site
Nintendo Switch Online members at over 32 million, service will be improved and expanded
Compra Barato Nintendo Switch Online Membership (EU) Online - SEAGM
Nintendo Switch Online 12 Month Membership Card NINTENDO SWITCH ONLINE 12M SUB - Best Buy