is there any way I can boost water pressure in my shower? I tried changing shower head

Did you look at the flow restriction device inside the head? This are a little dime sized piece of plastic, though sometimes they are stainless steel with a small hole in the middle. If you drill the hole a bit bigger you can improve the flow.

What is the flow like without a head? Take the head off and hold a bucket to catch the water and time how much water is coming out of the unrestricted pipe in a minute, or half a minute and double it for gallons per minute.

It is possible to get good pressure and spray pattern with a good low flow head. Since you replaced the head the head is not likely the problem. They can get clogged up with mineral deposits.

How old is the plumbing and what are the pipes made of?

good advice from sparky..
another cauise could be. a scald guard on your showerr valve. if you have one.
if you do, readjust the scald guard to give you more hot water.
if that doesnt work then you have the dreaded calicum deposits the only fix for it is to take valve out and replace

Perhaps I should have been a little clearer. I have low water pressure in whole house .The only place it's really an issue is in the shower. I was wondering if there was anything I could install (booster pump) to help increase the pressure

go to a plumbing supply house
ask the guy to give you a hundred lb gauge that screws onto your outside hose bib
screw it on, tyurn water on and ck the pressure
if under 50 psi. ck water pressure at meter
might have to disconnect meter and add a nipple to use your gage
ck and see if you have a pressure reducing valve installed at meter or where house hooks up to main service line
you might have a old water service tyhat is old galvinized piping. i9f so..rip out and replace with a pvc service
need to know psi at house first.before go another futher

From my experience, low water pressure is caused by a restricted main line well over 90% of the time. especially if your main line is galvanized, by now the interior is all rusted crud with a working diameter somewhat less than a pencil.

Have your water company to a pressure test at the meter, then test the pressure as near as you can get to the input to the house. Don't just go on the initial pressure as the restricted line will still build up pressure, just will have a low flow rate.

Unfortunately, the fix is installing a new main line from meter to the house.

most plumbers, as a rule of thumb
will install a faucet. directly above, where the main water line from meter ties into the house piping
8 times out of 10, dig down under a faucet im the front of the house. you will find the main line
that info, may or may not help you find the main water line