Any advice for a shy guy?

Hey! This might be a bit weird question but anyway ... There's this guy I randomly came across on Grindr (I'm not really into one-time actions but you never know who might be out there). We exchanged few casual messages, he expressed his attraction towards me and added me on instragram. We also matched on Tinder after some time and continued our conversation a little more but nothing too long. Though every time I messaged him, he was very nice and calling me "beautiful" or "cute". He claims on his profile he likes to meet new people but who knows what that means ... also he's very attractive and half of the gay community of this city follows him on Instagram, etc. --- he's simply popular. And I'd like to ask him to go out ... but how? Or should I avoid this type of guys?I have had only two boyfriends (I'm 25-ish, sorry, don't want to specify many details, I'm a little paranoid), both +3 years relationships so I'm not super experienced in flirting lines as I never needed them. I'm also really shy though many men told me they like me (both personality and how I look), I can't really do much with that, it's just at the beginning, then I'm fine ... AND the last thing is that I feel very insecure doing anything right now because my first language isn't English so I have pretty heavy accent and when I'm nervous, I can mess up with grammar, hahaAny tips on ultimate flirting lines? Lol, no, I'd be happy for any advice. Thank you xxx Matthew