I have a Trek Fx 7.3 which from what i can tell can hold a rack and bags.

right now all i use is back pack when i ride up to our local library, corner store, or video store etc.

I would prefer to sometimes get some goods in quanity with my bike instead of car.

please recommend a good set up for me.

A standard rear lugage rack with a pair of panniers will carry a large and heavy load of groceries. Take care with heel clearance: my panniers have a cutout profile on the front edge for extra clearance. You need stiff, tough material, goos stiffening board on the back and base and for safety, a locking, quick-release mounting system. Hook and elastic are used on cheaper bags but are totaly obscelete and can bounce off.

The cheap way is a good old wald 520 pannier basket, about 25 bucks . They look goofy but I have one on the townie bike and it is super convenient for food shopping or going to the hardware store.

https://www.waldsports.com/index.cfm/...rcarriers.html

$25 for a Wald basket is cheap, or even Walmart sells cheap handlebar baskets for $15. Or if you want a cheap pannier set up, Blackburn makes very good racks for a low cost, and you can find inexpensive bags to go on it at most LBS's.

Why limit yourself to what you can carry on just the bike when for less
money (depending on your salvaging skills) than a Wal-mart basket
you can own and use a trailer that you can build for about $25??

"For those who want a "afforable" trailer consider a DIY trailer like this one. I built this trailer
many years ago using easily salvaged material that were found or I had on hand. I use it still
today when my Worksman PAV trike can't handle the load. If you elect to follow my mods to
the original plan it will have load capaicity of 300 lbs easy.

https://www.motherearthnews.com/Do-It...e-Trailer.aspx

My mods.....
Frame... from plywood to white oak salvaged from a shipping skid.
Wheels...from 27" to 20" salvaged from a discarded kids bike (carrys more).
Neck.. from plywood to white oak salvaged from a shipping skid.
Bracing for neck (for added twist strength) diagonal from front edge of frame to 6"
behind hitch of 3/4" electrical conduit. Neck dimensions can be adjusted to fit properly.
Paint...what I had on hand in oil based enamel.
Hitch.. a piece of tire side wall or other cord reinforced rubber sheeting.
Safety... seat belt for kids and bike flag for idiot drivers.

This plan is so easy to build I built mine using simple hand tools for everything except
drilling the 4 holes in the metal conduit."

Totally agree. I own one just like this I got from Western Auto and you can use them for about anything and they are tough as they come. Also 8 million ways you can tie or bungee stuff down using those.

Trek makes a nice rack that you can use with their Interchange pannier bags. I bought two of the "grocery bag" panniers. They come off in a flash and have handles or you can use a shoulder strap. Easy enough to use them as shopping bags. The bottom folds out to form a wide flat surface that will hold a lot of stuff.

There is design and plan for a really strong, lightweight trailer made from bamboo.

Thats exactly what I had for my paper route when I was a kid! memories....