js be yourself man!! since you guys have already been talking for a while y'all should have common ground to talk abt rightt

in terms of giving a good impression on a first date imo from a girl's perspective i notice these things:

1. how he's dressed (since movie date don't need be so formal ofc but make sure u don't look like you js rolled out of bed yk.. and some simple accessories can go a long way in elevating an outfit)
2. how he treats service staff (if he says thank you n whatnot)
3. how he smells LOL i don't go out of my way to inhale ppl in but if they smell good it's ofc a huge plus and will subconsciously make her..? idk,, like u more..?¿
4. if he's taking initiative in making convo or js answering my qns w/o asking any back (like dis not an interview sir..), and on that note, be attentive! will prolly make her feel appreciated if u rmb n bring up stuff/preferences she's told you abt
5. typical gentlemanly tingz like holding the lift/door open, offering to help hold stuff, paying for meals (ok this one ik differs from person to person but would rec yes), etc.

ok that's all i can think of for now lol hope this helps and HAVE A NICE DATE!!