By the way, Budapest is a ‘top’ place, so use the top cases with it. These are: ‘to the top’ - -ra/-re, ‘on the top’ - -on/-en/-ön/-n and ‘from the top’ -ról/-ről. To, in and from: Budapestre, Budapesten, Budapestről. The ‘on the top’ case is one where roundedness makes a difference, but only for front vowels.

When we go to a place/countryside. Use -ra /-re or -ba/-be Budapestre, egy üzletbe(store), étterembe (restaurant), Párizsba( Paris), Londonba (London), a városba (to the city)

-nak -nek can mean for :

I need to buy an anniversary gift for my friend. - Kell vennem a barátomnak egy szülinapi ajándékot.

When we visit a person:. Use -hoz/- hez / -höz. or -t

I go to the baker. -Elmegyek a pékhez.

I visit Peter. - Meglátogatom Pétert.

https://en.wiktionary.org/wiki/-hoz

Yes, there must be a subtle difference between "esik a földre" and "leesik a földre," and we would be glad to see the explanation.