Is it human or synthetic? There are several solutions to make a wig feel more secure, depending on the amount of hair you have underneath. Eg
You can get clip combs from amazon that you sew around the wig edges
You can put your bio hair in a low pony and pin it up flat - the ‘knob’ of the pony creates a bump that stop any riding upwards.
You can wear a wig cap, either net or nylon (not a normal hairnet). I find this my least preferred solution.
You can use a product called ItStays from ebay or Got2BGlued from boots as adhesive if you don’t have much hair
My preferred solution and I have never lost a wig is a simple velvet wig band. (Amazon). It sort of Velcros the wig into position. It’s super comfy and that wig goes nowhere.
Finally, use the adjusters inside to get a good fit.
Choosing the right colour, especially a highlighted or rooted one can also help with it looking natural, as can a mono top, which gives you a natural part. Lace fronts will give you a natural line at the front, but you don’t need one with a fringed wig, and some people find them itchy.
However, having said all that, if you have hair, I’d seriously reconsider a topper. Loads of brides wear them, anyone who does bridal hair will be able to do you a decent updo, and it might feel more ‘normal’ for you. I love a good wig, but they do take time to get used to. Hugging etc doesn’t shift your wig, but if you feel nervous about people bumping too close to your head, it will spoil your day. A topper may well work best.
Whatever you decide, have a lovely day :)