It's tough when our friends get busy and schedules don't align, but that won't always be the case! Maybe try and schedule some time with your friends ahead of time, even if it's just for a phone call or facetime?
In the meantime, there is always someone around in our discord server or over
PM to talk and you may be able to find some friends that you share interests with on here. Additionally, if you're too anxious to go to the park or mall alone and that's something you want to work towards being able to do, maybe start small and work your way up to those kinds of outings. For example, if there's a park a short walk from your house, one day take a walk over and sit in the park with a book or a good podcast for a bit before going home. It doesn't have to be for long, just to ease yourself into feeling comfortable going places and spending time alone. I know I always found it helpful to ease myself into those types of situations, I used to take long walks alone listening to my favourite CDs or playlists, then I started going to small coffee shops to read, etc.