can't find FTP nor emails

i’m new to the whole linux and web hosting thing,
i managed to install webmin and virtualmin on my VPS hosting and i managed to host a wordpress website, all that with the help of google of course,
i have few questions that i want to ask because i still don’t know some stuff and could not find answers on the internet,
1- i don’t see the option where it says, FTP and emails on my virtualmin, i have no idea what is my FTP login info and what if i need to install FTP program in my virtualmin or not, i managed to install wordpress using file manager,
2- i have no idea how to check emails in my virtualmin, i can’t see any thing related to read my emails.
3- my vps using 512mb ram and after installing webmin and virtualmin and wordpress the ram become around 350mb used so there is just a little bit left, and i still did not install spam security programs nor anti virus because i read in this website that they use a lot of ram and did not installed any wordpress plugin’s yet nor theme, , so how i can optimize my ram? i just want to host 1 website and i thought 512mb ram will be enough but seems i’m wrong, it’s new website so there no traffic yet,

i would appreciate any help,
thank you