Advice on eating before running

Hey, I’m looking for some advice. I’ve recently picked up running again and I’m on week 9 of a Runna new to running plan which so far is going good. But I’ve got issues with eating beforehand like I never know what to have to give me enough energy while I run. My runs can be anywhere between 20 and 40 minutes, and normally I run after dinner, but I’m now on holiday so I went out about 11ish this morning for a 1.75km continuous run at speed 7 on the treadmill and just about threw up after I was finished. I’ll admit I pushed myself because I’d missed 2 previous runs but I also think I hadn’t fuelled myself up enough so basically I’m hoping anyone would be able to help me out. Thanks! ☺️