I’m planning to make a jack that has 2 inputs.

will this work? or will it mess up the amp or guitar.

need someone with experience

Benny’s suggestion is valid, but if you want a little more versatility then you might want to look at an A/B or A/B/Y switch. This will let you turn on each amp individually or run them together.

http://pro-audio.musiciansfriend.com/product/ART-CoolSWITCH-ABY-Box?sku=180614

That’s an entry-level box. The better ones will have transformer isolation between the two outputs to prevent ground loops:

http://guitars.musiciansfriend.com/product/Radial-Tonebone-BigShot-ABY-Passive-Switcher?sku=153931

And of course, the sky’s the limit. Some will also incorporate signal boost and programmability:

http://guitars.musiciansfriend.com/product/Radial-Tonebone-JX2-Pro-Switchbone?sku=153908

But, at least this gives you an idea of what’s out there.

Just be sure to plug both amps into the same power strip to minimize the ground loop. But splitting the guitar to 2 amps is no big deal and won’t mess up anything.

Good luck.

Greetings from Austin, TX

Ken