I have to suggest getting a new computer. Pentium II are ancient, it will be very very hard to find a processor that will work with that mobo. You can get a new computer very cheap that will be lightning compared to the computer you're trying to upgrade.
You may be able to find a processor to upgrade on ebay or something if you can't get a new computer. You should try and find out what socket that mobo uses to find a processor that will work.
I really suggest investing in a new rig. you could get a pretty decent system for less than $500, and it'll be nothing compared to your current computer.