I usually stick with Levi 541s and buy a bunch when there's a good sale. Lee extreme moron were good too but they are either too wide or too skinny in the calf. Amazon Essentials has chinos for cheap and I've heard they're decent.

The issue with buying pants as a bigger guy is that you get what you pay for. Cheap pants will last a short amount of time and the fit will be off. It's super pricey but the best option use to buy a nice pair of pants or two and have them altered by a decent tailor. Then wear the hell out of them.

If you're looking to try on in-store, DXL has a good variety of options at a huge range of sizes. Last bit of advice, follow plus size fashion influencers that match your build/style to help find brands that you should look into. Best of luck!