I also made that transition and the comments above are great advice but made my own jumps that adjustable and can be knocked down easily. If you aren’t very crafty just ask your local hardware store or buy one. I would suggest if you are jumping 2ft or less (excluding quarters and some smaller boned arabs) that all you would need is a close contact saddle or all purpose saddle and saddle pad and depending on the horses fit a half pad, and a bridle. For a girth I found girths with cotton or fleece stay on better without rubbing or slipping. If your horse likes to over extend I would recommend boots for the front legs (When switching horses will extend to meet the strides they need to clear a jump while other english horses may either extend or collect) I use polo wraps to keep my horses tendons protected a little bit more and they are inexpensive for a good pair. Obviously I would wear english gear (trust me jumping in western boots gets your boot stuck on the stirrup and is very uncomfortable and if you try it, most likely you will see what I mean) At least the breeches and some sort of boots I would get (unless you plan to show get the whole attire) Finally if you are jumping more more than that (or if you are jumping more than 1&1/2 for small breeds like quarters and pony breeds) I would definelty wear some sort of protection on the front feet and shoes (I am always barefoot unless Im going to congress or on my jumper) and a breast collar and all of the above. Yo dont need super fancy stuff just moderate. (again unless you are showing big time I would not worry how nice looking your tack is just durable. Hope you have a great time with the new skill!! Sorry for the long read. ps I could jump pretty well but I took 3 lessons and really helped (they were only an hour long) I would HIGHLY recommend this so you dont practice wrong cause jumping is muscle memory.