My husband is a trucker and sometimes I like to go on the road with him, now that I have goldies Im worried about what they can eat while Im gone, my bettas are hardy and I feed them a huge meal before I leave and when I come back they get another huge feeding and they are fine , are gf the same? I was wondering if I need to buy those self feeding cakes that either sink to the bottom or stick to the side of the tank walls?

Healthy fish can go for 2 weeks without being fed. Instead of adding the blocks which are low in nutrient and pollute the tank, buy some plants such as elodea for them to munch on while you are away.
Do a 50% water change after a feed and dont add any food to the tank after.

Like Sandy says, avoid using those feeding blocks they can really mess up your tank, they can be very unreliable in the way they break down.

Also, personally I would avoid giving huge feeds to either your bettas or goldies before going away. A usual size feed, followed by a water change as Sandy says should be sufficient. You can then either leave a nibble plant for the goldies or give them a treat went you get back and are around to keep an eye on the water quality

Would lettuce or zucchini work? I bought live plants for my tank when I got it and Im deathly afraid of bugs and within a day noticed flatworms and damselfly larvae in the tank and did a 100% change and scrub and went plastic plants, but if I have to I guess I can buy a plant and keep it in a seperate gf bowl and just "harvest" stalks and throughly wash them before I add to the tank for long term feedings.
I didnt mean I gorge my bettas, like I said they are severely hardy, both are a year old so they are used to me being gone for long periods of time, they get a 5 peice feeding before I leave, and I always do a 2 week 100% change since they share a seperated bowl.

I'm not sure about the lettuce or zucchini because unlike an aquatic plant they won't actually "live" in the water and any uneaten pieces may pollute your water while you're gone, I'll let some one else confirm that

I'm sure you look after your Bettas really well, what I was trying to say was that Bettas have a fast metabolism so more food equals more waste, which is not desirable if you're not going to be around to change the water. However, a large water change before you go sounds good

Oh, BTW welcome to Koko's!