I don't know if this is really the place for this question but I read a fantastic article about this:
There's way too much information in it to present in a single SE answer, unfortunately. It describes the process of generating made-up words and languages yourself in a way that doesn't require any programming knowledge (you could use an online RNG, for example).
The basic idea is that you come up with a number of character sets, a syllable structure, a word structure and a set of morphemes (not all of those steps are necessarily required) and then you choose from them at random.
As a simple example, you might choose:
Consonants: b, k, m, n, t, sh
Vowels: a, e, o, u
Syllable structures: CVC, CLVC, CLV
Word structure: 1 to 2 syllables
Now first you would choose a number of syllables at random, then decide the structure of those syllables at random to come up with a few words:
CVC, CLV-CVC, CLV, CVC-CVC
And finally fill in each letter at random:
kem, shlabot, blu, tebmun
Depending on how you choose your letters, you may need to throw out a word every now and then ("tlo" is hard to pronounce) but otherwise the result feels natural. Because they use the same letters in the same ways, they all feel like a unified set of words even as they're chosen at random.
The article goes into a lot more detail that will teach you very briefly about phonotactics, orthography and morphology, which can help you develop more complex nonsense languages that despite being nonsense still feel real.
There might be canned online fantasy word generators out there, but using this method you are in complete control of your end result.