Has anybody ever been to Makarska? Are there nice sandy beaches? And do you maybe have some tips?

Makarska is a nice town, the beach is more or less in the city (on the left side the boulevard and on the right side the beach).
The beach is not exactly sand, it is more made of small stones, but comfortable.

Makarska can be extremely busy, so don't know if you will really have a lot of space on the beach for yourself.
Parking is a bit of a mess as well and you may end up parking your car on top of the hill, having to walk down to the city center.

But, I think you can have a nice time in Makarska and even Dubvronik is not too far away.

Do you also know some restaurant there where i can eat well and the prize is not too high?

hotel biokovo pizzeria (right on front) for very cheap and very good pizza/pasta
prawn tagliateli especially good.

susvid - on the town square typical grilled meat/fish dishes. very nice people scampi on a spit especially good

porec - on the front upstairs, scampi risotto superb hot cherries and ice cream very good (for somewhere that doesnt do desserts)

riva on the front - exceptional scampi rissotto

much more expensive but the best in makarska riviera imho - restaurant jenny - 5 min drive out of makarska above tucepi.