Does the tube need to be hollow? Do you want round or square(ish)?
What does the surface finish need to be? Relatively smooth or glass smooth.
You mention laying it up on a piece of foam. Would you then need to remove the foam?
The foam can add a great deal of strength to a structure. Think of it as the center web of an I-beam. The foam will help resist buckling of the skin.
If the tube is to be round, just laying the fabric over it and wetting it out might work. If there are to be any sharper corners you will need to wrap the layup with something to keep the fabric in contact with the foam and each other. You should wrap it no mater what to compress the layers. They make a specialised shrink tape that you wrap, then hit with a heat gun. You could use electrical tape, or that plastic cling wrap stuff they use to wrap pallets. Or place it in a bag and draw a vacuum.
If you wanted to use a female mold and it's to be round, a length of PVC pipe split in half could work. Use car wax as a release.
Lay the fabric so that one edge is just below the edge of the mold and the other is above by 1/2". Do the same thing for the other half of the mold, then when you put the two halves together the fabric sticking up laps over the other side forming the seam. Make the layers the same width which will stagger both edges. Staggering the edges of the layers (first sticks up 1/2", second sticks up 5/8", third stick up 3/4") will make it easier to not have large voids in the surface along the seam.
After wetting out all the fabric in the mold, add extra epoxy along the seam and on the fabric sticking up. Brig the two halves together carefully so you don't catch the fabric and clamp the mold together. Then use a stick to work the fabric that was sticking up. This laps over the other fabric edge forming the seam.
Orientation of the fabric should probably be balanced. One layer at 0-90, the next at 45-45 and so on. What is the reason for the Kevlar? Kevlar will help keep the thing together should it suffer an impact, but won't add much otherwise (my opinion, may be wrong).
Use a laminating resin such as West System, ProSet or MGS. If you try to use a 30minute epoxy glue you will end up with a mess. West System is probably the easiest to find. http://www.westsystem.com/ss/where-to-buy/
West System is also a lower performing resin compared to ProSet or MGS. ProSet is better and MGS the best (of the three listed). West will still yield a good part, but the flexural modules, heat deflection temp and other numbers are lower than the other two.
You can use a spray adhesive to help keep the fabrics in place somewhat. A light mist of 3M77 over the fabric (while it's flat on the table) can help keep the fabric together once cut.
Use gloves (no latex). Epoxy can cause allergic reactions in some, and you can build up a sensitivity to it over time. Some I know can no longer use epoxy their reaction is so immediate and severe.