Anyone altered the dress at home?

You can do anything you like. People won't be able to see the sequins and beads you add to the train unless they are a contrasting color so I wouldn't personally go to the extra work of it.

People do it all the time. Except I would not use plastic sequins. But seed pearls and glass crystals, sewn on with clear monofilament thread, sure.
Do not use hot glue. Many synthetic materials melt at very low temp, leaving a field of bumps under anything hot glued. So make sure everything you buy has a drilled hole for sewing . start with glass beads, or crystals less expensive than Swarovski, or seed pearls or faceted glass beads or faceted gems, or sew on faceted rhinestones.
firemountaingems.com They have many designs to look at too.

View Quoted Comment Great advice! Thank you. I will start looking online 🙏🏻

I have not but I have heard of it several times.

View Quoted Comment I agree with this

Www.firemountaingems.com/itemdetails/h20a2218gl
These are the faceted bi-cone or 2 cones crystal beads, clear glass. About 10 here, they come in all sizes. They are cut in a little prism, so that they reflect dots of light, and tiny rainbows in sunlight, pinpoint, so they seem to glow. Less is more in beading. But even a simple loop-de-loop along a hem, with or without a few seed pearls in a design, of white tubes of bugle beads, are pretty. Like a mosaic tile design, something simple repeated again and again, easy to do, is quite effective. This is like a vine inches up from a bottom edge, with tiny bicones, and round seed pearls. This sort of design is a pretty motif, but you would not want to do too many on a train hem. Crystals, enough of them, are weight.


Little cut glass diamonds.
these are oval seed pearls, with a soft luster, used with a fine wire blown up almost 2 x actual size.

This type simplicity, with just a faceted bicone, or a seed pearl, is often done on the lower hem of veils and trains so they will not blow everywhere in windy weather. ... And the simple scatter, 1 to 3 beads or crystals in a cluster, not in rows but scattered every 4-5 inches , or every 7-8 inches over the lower train will just be sparkle points, and not compete with any beading on the bodice. This scatter of bicones, and an outline of a neckline on a plain dress, are the most common do it yourself. Knot 1 bead at a time. Good luck.