additional IP address - beginner question

You can file a support ticket with your business case. Wanting to run multiple websites is likely not a valid case, however.

You could also operate them from two different Linodes, perhaps on two different accounts… separating personal things from business things is a good idea, and will probably make your accountant (and attorney) a little bit happier.

Depending on the level of "anonymous" you're hoping to maintain, and against whom you're trying to maintain it, you might also want to consider hosting the personal stuff somewhere like NFSN. I mention them in particular because they're relentlessly discreet and entirely pay-as-you-go.

I forgot to reply to say thanks sorry. I asked Linode for an extra ip but they said no. Appreciate the NFSN suggestion. Thanks!

Unfortunately, Linode has had to be stricter with IP allocation rules since IANA ran out of them. IANA controlled the global pool of unused blocks; they allocated the last free blocks to RIRs in February 2011. After that, the RIRs have started running out of unallocated blocks. APNIC (Asia) and RIPE (Europe) ran out of full unallocated blocks (have less than one less each), ARIN (North America) is projected to run out in about 10 months or so, LACNIC (South America) in 2015, and AFRINIC (Africa) in 2019.

tl;dr: IPs are scarce now, so Linode (and theoretically everybody else) have to be stingier with them.