first off mate, don't even start thinking about what you should or shouldn't have done, theres no point and you just waste time and energy doing so - you are where you're at, and this is therefore the right time for you and when you're ready. Look on it as a positive, a new start.
second there's a lot of information on this site if you search the ask a gay man, from lots of guys in similar position to yourself, so go read the ones that interest you - most guys on here would be happy to chat with you one on one if you like a particular post or they have been through similar to yourself - nothing like peer support to help you through this. There'll also be lots you can find about playing with yourself, getting used to the feeling of touching yourself, feeling something inside you - plus even during lockdown you can order toys on line to be delivered
third join other dating/hook up sites, as the previous poster said, at this time you'll get a lot more chat as you can't meet up - do be upfront, theres nothing to be ashamed of at being a virgin at nearly 30, it is what it is. If you're upfront about your situation and therefore what you're looking for, those that aren't into virgins will avoid you and you may connect with someone who'll happily work with you on discovering your sexuality.
fourth, as a fellow introvert I know how hard this is, but join gay clubs - there's lots of gay sporting, walking and other clubs where gay men meet, even if only to get used to being around other gay men, which you may not have experienced - it'll help normalise how you feel and being gay just seeing other gay men around just being gay men
finally, this is fun, go out and enjoy, you're still very young and have plenty of time to be who you want to be