The book Super Baby Food really helped me! Buy a copy or check your local library. I never bought one jar of baby food! You can get a food processor, but there are also many foods you can mash with a fork to start with. Avocados are easy to mash and have a good fat that babies need and the taste is bland enough so it's a good first food. (You do NOT have to feed them rice cereal! You can go with a bland fruit or veggie like sweet potatos.)
So with an avocado, cut in half and remove the pit. You'd want to do a few at a time. Then scoop it into a bowl and mash with a fork. Get out a cookie sheet and lay down some wax paper. Drop the avocado in big spoonfuls onto the sheet and freeze. It really only takes a couple of hours. Then bend paper to remove droppings (they look funny!) and drop them all in a ziplock bag and store in freezer. Label with Date Prepared - check the book. You want to use up most frozen foods in 3 or 4 months I believe. Probably not an issue with twins!
When it's time to eat, just take out a couple of droppings and put them in a dish to thaw in the microwave (it doesn't take long to thaw, make sure it doesn't get hot!) or leave a few in a covered dish the fridge the night before. I used the small tupperware/rubbermaid style cups with lids to feed from! Ditch those baby bowls that don't have lids! It helps when you're making it if you know about what your kid will eat in 1 serving, but you can do smaller amounts and thaw more than 1 at a time. Since you have twins (assuming they both eat the same foods) you could thaw 2 or 3 or 4 each meal time.
When you get a food processor, you can make batches of any food and freeze in a similar way. In the beginning, there aren't really "recipes" you just mash up a veggie. It goes like this... Soften some sweet potatoes in the microwave and remove peels. Use a spoon to scoop flesh into the processor and turn it on. Blend until smooth for younger babies, then as they get older they can handle a little bit of texture and you don't have to blend as long. From there, spoon it into ice cube trays and freeze. Once frozen, you guessed it, transfer to ziplock bags and label. You'll probably want to thaw 1 cube for each baby, or more depending on how much yours will eat.
You will get the hang of it! Read the book though, it has great info of what babies need at each stage and some hit the stages earlier or later than the average kid, so you don't always have to go by the book. I started my son on solids around 7 mos and he was not big on eating until nearly 12 mos. Preferred the boob. We did not force it since he didn't seem ready (and mealtime was pretty frustrating) and preferred to feed himself with cheerios at 8 mos. So we found finger foods and he got happier about eating. Anyway, my point was that while the author started feeding her babies at 4-6mos, we were at 7-9mos looking at the 4-6mos chart and so on. Do whatever works!
And good luck!!!