Hi guys, Im new here and hope to have my life changed pretty soon

i know this question has been asked a few times already.. but I just want to ask it in a different way and added with another question that i havent seen asked on the 104 pages on this forum.

1st. Im new to systems.. im orderingg mine within the next week or two.
I have a gf and i dont plan on telling her about it yet. Im only 24 and im just not comfortable telling her anytime now till the next 6 months. I have a pretty full head of hair that looks thick with a concealer. but now the hair is really thinning and i think its time for a piece. I dont think il find maintaining it so hard as ive had to deal with over a year of toppik.. spending about an hour a day looking into the mirror because i am a perfectionist.. some days id make it look great after being gelled. and some days i woul have to cancel my plans because i just could not make it look great. So i assume i am mentaly prepared now for a system.

My main concern is.... Im planning on getting sfs and since i havent worn a system and i havent seen anyone with one im wondering how the lace in the front goes invisible? i mean it is a physical object.. how far from the hir line to the forehead does it go down? does it stop at the last strand of hair in the system or does it go further? If someone is sitting right infront of you and you two are having a convo at a retty close distance will someone be like. "yo dude, u got some material thing on your head" I learnt so much after researching tis forum.. but i havent fund any clarity on this.
Also, my last question..
You know, when u go to those bowling alleys that have that glow in the dark thing going on? it usually turns ur white clothes green? will that change the color of your lace or not? like should i plan on staying away from black lights and glow in the dark themed places?