1. Unless you live in an Orthodox community, keep a strictly kosher home, and have the full range of kosher foods available to you, you’re going to either break the Orthodox rules for keeping kosher at Passover or starve. I always vote for a slight breaking of the rules over starving. Call me irresponsible, but that’s just the way I am.
2. So, what to do? The key rule is not eating leaven, and, in its basic form, this is doable. Leaven is any grain that is not first converted into matzah and then eaten. So, not only is bread leaven, but noodles, cereals, crackers, and cakes that are not specifically prepared for Passover, with Matzah flower, are leaven. Therefore, pizza, breakfast cereal, and pasta are out. Sorry.
3. Now comes the hard part. The Ashkenazic rabbis (the rabbis of Europe, except for Spain) added a bunch of rules to the ones about not eating leaven, just to make sure we didn’t come close to violating the Passover rules (this is known as “building a fence around the Torahâ€). By their reasoning, because one could make flour that resembled grain flour out of chickpeas, peanuts, corn, or rice, one had to avoid not only flour made from them but the legumes, corns, rice, and peanuts themselves. Even their oils and sweeteners were off-limits (like high fructose corn syrup).
4. What to do? Here’s where you get to enter the picture and make a choice. As a Jew of Ashkenazic heritage, or as someone who became Jewish under this tradition (which covers the majority of TBI-niks), you might choose to avoid the corn, peas, rice, and peanuts.* Not too, too hard, but given that we live outside of a closed, Orthodox system, you might struggle to avoid the oils and sweeteners made from these foods (start reading packages of food and you’ll see what I mean). So, if you find respecting the rules about corn etc. meaningful, you can choose to avoid foods that use these oils. But if what you want to do is meaningfully observe the Jewish tradition of not eating leaven at Passover time, then not eating rice, corn sweeteners, etc. may seem to be beside the point.
5. My advice is to keep your observance dynamic – few of us succeed in following Jewish rules that feel technical and baffling, and worse, trying to do so often results in us dropping the rituals and practices that we love. And notice, two out of three of the world’s major groups of Jews (Sephardic and Mizrachi) decided that things like rice, and corn oil were okay for Passover. Committed Jews are not monolithic in how they practice their Judaism.
6. The upshot. Avoid bread, pizza, pasta, cereal, and baked goods not specifically made for Passover. Make a choice about whether to eat rice, corn, corn oli, high fructose corn syrup, peas, and peanuts. Everything else, salads, meat, eggs, cheese, chicken, fish, potatoes, nuts, fruit, and veggies, you can go ahead and enjoy, anywhere, anytime.

Congratulations on making the choice to seriously observe the Passover food rules. Remember, you’re not alone in trying to figure out what to do. Every year my family, all of us, rabbi to kids, encounter new situations that we have to talk about and figure out what to do (I’m still recovering from my discovery, while in rabbinical school, that peanut butter was traditionally out of bounds for Ashkenazic Jews). Passover observance is a lifelong learning process and if you’re asking the questions than you’re already being a responsible and committed Jew.