First property and another newbie question!

[Tom Port]

Hi Guys! 

I posted my first question just under a year ago but I just bought my first property in the United States! As a non-citizen it took a little while and it is just a residential but it's still a big step for me. 

I am in a fortunate enough position to have a chunk of money that I now want to put to work in investing in more properties but my question is; My credit score is currently "Not Good" Not because I've been irresponsible, but, because I've not lived in the US for very long. Shall I wait and improve my credit score? Or shall I get prequalified now and start looking accepting that my mortgage rate won't be great? 

Any advice is hugely appreciated!