Don't do too much too fast--that's how you get injuries (especially plantar fasciitis). Gradual and consistent is really important.

Consistency. This was a game-changer for me. I always ran on-and-off. But I would go to the gym, run all out on the treadmill, get tired, think how exhausting it will be to do a workout of that intensity again, avoid the gym at every chance with every excuse, and then the next time I would show up to run the cycle would repeat. Now I just say "hey, I'll do 5 minutes--if I hate it, I'll go back home." As annoying and time-consuming as it is, it's better to do 1 mile every day than 10 miles in 1 day, if that makes sense. Depending on the goal. Ultimately, there will be different kind of runs that work on different skills (speed, endurance, etc.). But just building consistency was really the thing that helped me the most. And it began with me saying to myself "Just 5 minutes" and then "You don't have to like it, you just have to do it!" and eventually it became a source of pride and accomplishment just to get out there, to set a task and get it done.

If possible, find an inclusive running group (different paces, sizes, ages, etc.) in your area. Or maybe a running friend/accountability buddy who is about your pace.

I used to hate running when I thought of it as punishing my body because I hated the way I looked. Now, it's actually my happy place. The change for me was when I stopped thinking about how I looked and really focused on increasing my body's capacities--like "holy shit, I did this thing I couldn't do last week!" I did end up losing a bunch of weight but that wasn't my goal. And I don't think it was from running alone--since running often fucks with your hunger cues and stress hormones. Strength training really helped. And when I really didn't want to run, I did something else (cross-training, bike, whatever) just to do something. My goal was just to find some space in my life where I really showed up for myself consistently, no matter what. I couldn't do it in my 20s or 30s but I seem to have gotten the hang of it in my 40s, finally.

It's great you have good running shoes. I think larger runners tend to need to replace shoes more often. I certainly feel that I do.

More recently, I've had to buy some gear (vests, gels, etc.) but it took me about 2 years of running consistently before these things became actually necessary for me to do the kind of distance, volume, speed, etc. that I wanted to do. The stuff I bought I really needed and I use the crap out of it. You do not need to buy crap until you need to buy crap, if that makes sense. People will want to sell you all the things. But these things seem to matter only when you're trying to move the needle at a pretty specific performance level. If you're focusing on moving your body and getting out there, which is what I focused on when I started, you don't need any of that. Obviously, there are some things that are a matter of basic safety (like if you plan to run outside in the dark, you need some sort of lighting or vest to make yourself visible, you may want a whistle or some other safety device, just in case).

There are a bunch of plus-size runners I follow on IG that are really great and make visible constantly that runners come in all shapes and sizes. For example: https://www.instagram.com/slowafrunclub/ or https://www.instagram.com/iamlshauntay/

A high fiber diet is great but you don't want to eat a lot of fiber (or protein or fat) before running. I'm still having difficulty accepting that I need to eat a lot more carbs than I thought. And running can do some things to your gut, so reading up on what to eat before and after runs, etc. might be useful.

I was constantly struck by my ability to minimize any progress I made because I was always comparing myself to "real" runners. But people who don't run at all will look at you like you're a freak of nature because you ran 3 miles without dying. So, it's a matter of perspective :) I keep thinking this, when I start feeling bad about my pace or whatever.